fal Caretaker Prime · dev log
Dev log · 2026

Caretaker Prime

A cel-shaded creature garden: raise a few memorable creatures on an overgrown island that keeps living while the game is closed. Think Chao Garden care, Stardew restoration and Animal Crossing coziness.

Built in Unreal Engine 5.8 on a Mac by a team of AI agents directed by one person, with every art and sound asset generated on fal. This page documents how, including what didn't work.

Work in progress · two playable islands, a real caretaker, creatures that grow up, crafting and gathering, a house to decorate, farms, and furniture the creatures drag around · updated as we go

Cel-shaded concept of a lavender crystal-rabbit adult creature holding a fruit on a beach beside a rope-bound pier
Style anchor · adult creature on the starter beach · nano-banana-pro

Days twelve to sixteen: a house, a shop, and furniture everywhere

2026-10-10 to 10-14 · waves 15 and 16, alpha fixes

Five busy days. First, fixes from Kenneth's play of wave 14. Then wave 15, Home & Harvest: a house of your own, Animal Crossing-style decorating, a shop that drops out of the sky, farms and a boat dock to build. Then a round of alpha fixes: a startup splash, a pause menu, and two crashes. Finally wave 16, from a single playtest note: furniture goes in your bag, you can put it down anywhere outside, and creatures drag it around.

Honest status: Kenneth approved the trailer voice-over and made the design calls quoted below, but most of what's here is agent work. He is playtesting wave 16 right now, and the house, the furniture, the farms and the new animations are still waiting for his review.

Playtest fixes

2026-10-10 · arms at rest, worn paths, water, sand, grass
Two grown creatures, a blue finned one and a red winged one, each shown in five poses. In the before rows their arms hang well out from the body in an A shape; in the after rows the arms rest close to their sides

Creature arms, second try

angles pending review

The 24 degree droop from wave 14 didn't fix it: Kenneth still saw “odd t pose issues”. So we dropped the old diagnosis and looked again. Opus and GPT-6 Astra worked on it separately and found the same two causes. Three shared clips lifted the arms 67 to 81 degrees sideways, and the fixed droop still left the slim adults in an A-pose. The clips were re-keyed, and each body now has its own resting angle, as close to the body as it can go without a hand sinking into the torso. On a copy of Kenneth's save, frames with arms out went from 359 to 0. For each creature, the upper row is before and the row under it after.

Paths, water, sand and grass. Worn paths were drawn in blocky steps; their edges are now soft and noisy. Foam rings popped up offshore, which showed as seams in the water. The wet sand ended in a hard dark line and is now a soft pale band. And grass no longer grows on the beach or in the water. pending review

Not fixed yet: the caretaker's arms can look red. The character outline comes out red, and at the low camera it covers the thin forearms.

Wave 15: Home & Harvest

2026-10-11 · a house, decorating, a shop, farms, a dock
Six views of the same plot on Broadmeadow: a torn, overgrown canvas tent on a stone base; the tent repaired with a mailbox and a lantern; a small log cabin with a turf roof and a solar panel; a bigger cabin with a porch and a round window; a cabin with a side wing, a white dome room and an antenna; and the biggest version with a domed upper room and a stone chimney

A house of your own

pending review

After your first egg hatches, you find a wrecked camp on Broadmeadow. Claim it with materials, then grow it from a tent into a cabin and on up through four tiers. Each tier is a bigger project of materials and Supply Vouchers. The models are Tripo H3.1 multiview builds from one concept, recoloured to the concept's honey-brown. Kenneth asked for the two biggest to be smaller; he still has to look at them.

A top-down view into a small room with wooden floors: a bed with a striped blanket, a cable-spool table with a lamp, a crate stool, a cushioned two-seat sofa and a checked chair; the caretaker stands on a rug by the door holding a small creature, with a clock on the wall

Decorating, Animal Crossing style

pending review

The inside of the house is its own little map with a fixed camera per room. Furniture snaps to a 50 cm grid, turns, stacks (a lamp on a table), hangs on walls, and the walls and floors can be swapped. Some pieces can be used: sit, lie down, switch on a lamp, tune a radio. The catalog has 132 pieces, rugs, wallpapers and floors, in six themed series.

Two phone and shop screens. Left: the Supply Pod Shop with tabs Today's picks, Always in stock, Seeds and Sell, a grid of furniture such as a brass oil lamp, a spindle chair and a ladybug stool with prices in vouchers, and a Buy button. Right: the Critterpedia app on the phone, a grid of bug silhouettes with 0 of 52 caught and a detail card saying where and when to look

A shop from the sky, and a Critterpedia

pending review

The morning after your first hatch, a supply pod lands. Pry it open and it becomes the Supply Pod Shop: a daily rotation, an always-in-stock list, seeds, and a Sell tab. It's the first thing in the game to spend Supply Vouchers on. The workbench also learned furniture recipes. The Critterpedia moved into its own phone app (C), with a “New entry!” toast, and the HUD was redone with a time pill, the voucher wallet, a goal card and smaller creature chips.

Farms. Crop plots by the house, eight seasonal crops, a watering can, and rain that waters for you. Creatures with the Farmer job work the field. Creatures now only take things from containers outside, and the ones that steal give it back as a gift a day or two later. The boat dock is a deliberately big three-stage project (pilings, deck, boat) that ends in a bobbing skiff and a “Set sail” button that doesn't go anywhere yet.

The art, all made on fal: 84 furniture meshes, 44 farm props, 154 icons, 48 wall and floor finishes and the house from wreck to tier 4, with nano-banana-pro, the qwen multi-angle edit, Tripo H3.1 multiview and z-image tiling. Up to eight agents worked in parallel. After Kenneth's first look: bridges and docks no longer vanish when you stand on them, icons are never blank when a menu opens, and Kenneth left the voucher sign to us, so it's a V over an S.

Alpha fixes

2026-10-11 and 10-12 · the start of the alpha checklist

Things a real game needs. A startup splash (Squirrel Brain Games, “with help from” fal, then the title) hides the pop-in while shaders load. A pause menu on Esc or Start: resume, settings, save and go back to the title, or save and quit. The title's options menu was broken: a button scrolled about 200 pixels between press and release, so clicks missed, and hovering made it blink. Title and pause now share one options panel.

The game also crashed on every exit. Two console commands had the same name, and Unreal tripped over it while unregistering them on the way out. A test now checks that every command name is unique. Breeding and rebirth got a full self-driving test, which found a real bug: after a Farmer creature's rebirth ceremony, every save failed its check and the next load quietly went back to the save from before the ceremony. The caretaker got 21 furniture-use animations keyed in Blender (sitting, lying down, pulling a lamp chain, tuning a radio; still a few nits, like rockers that don't rock).

Kenneth approved  Trailer v4 re-shoots every shot in the current look, with an ElevenLabs voice-over take Kenneth picked.

Wave 16: furniture in the bag, outside, and on the move

2026-10-13 · straight from Kenneth's playtest

Kenneth, after buying a sofa: “I want the furniture to go into inventory like in Animal Crossing”, and “the reason is I want to be able to put furniture down on the island and creatures can move it”. And while he was at it: “also let's spin the house around 180 and move the shop next to the nursery entrance”.

So furniture now lives in the bag, one slot per piece, like Animal Crossing. Shop purchases and workbench crafts land there, and the house drawer stays as overflow.

Six frames on the beach of Kettle Island with a koi-patterned sofa: a green see-through ghost of the sofa in front of the caretaker; a red ghost near the water where it can't go; the sofa placed on the sand; the caretaker sitting on it; the caretaker pushing it along; and the sofa gone after it was picked back up into the bag

Put it down anywhere

Kenneth is playtesting

Select a piece in the hotbar and a ghost of it appears in front of you. Walk and turn to move it: green means it fits, red says why not (too close to the water, on the path, bumping into something). Then sit on it, grab and push, pull or turn it, or hold X to pick it back up. It works anywhere walkable on both islands, and the same Koi Sofa can travel with you from one island to the other.

Six frames in the long grass on Kettle Island: a small cream creature walks up to a koi-patterned sofa and starts dragging it; the sofa set down near the incubator with the toast Maple dragged the Koi Sofa over to the incubator; a baby creature carrying a red ladybug stool in front of it; a creature curled up asleep on a beetle-shell bed; and the ladybug stool by itself in the grass with the toast While you were away, Kiwi dragged the Ladybug Stool to the pond

Creatures move it

pending review

Each creature picks a favourite piece and naps or sways on it. A few times a day it drags it somewhere it likes: to its den when sleepy, next to a friend when lonely, to your door when it's bonded to you, otherwise to the pond or a sunny spot. Then a toast: “Maple dragged the Koi Sofa to the pond.” It happens while the game is closed too, and you hear about it on return: “While you were away…”.

Rough edges: creatures walk through big pieces (the furniture doesn't block their paths), the carry pose looks like they're holding the piece over their head, and a baby dragging a sofa is funny. Once a drag got stuck for no clear reason; drags now give up after 12 seconds.

Broadmeadow from above, before and after. Left: the cabin faces away from the main path, with the shop pod down in the meadow and long walking lines to it. Right: the cabin is turned around to face the plaza path, and the shop pod stands beside the nursery door under the cliffs, with a short line from shop to house door

The house turned around

Kenneth is playtesting

Before on the left, after on the right. The house now faces the plaza path with a short path to its door, and the shop stands beside the nursery door, so you see it every time you come out of the hub. The lines show the walk between them. The ground was rebuilt to match.

Playtest fixes

2026-10-14 · tree bugs, grab and push, pick up indoors

Tree bugs. Kenneth: “bugs are still hard to catch in trees”. The real cause: they were spawning 3.3 m up the trunk, out of the net's reach. Now they sit on the bark at reach height, and a near miss on a tree bug is forgiven.

Grab and push. Kenneth: “you need to be able to move furniture in all 4 directions and I can rotate stuff once then it gets stuck on the wall”. Now the direction keys move a held piece that way on screen, push, pull or slide it sideways, and a turn that would swing into the caretaker steps them back a cell instead of refusing.

Pick up indoors. Kenneth: “let's have the same behavior for all furniture everywhere”. Hold X now picks any placed piece in the house up into the bag too, along with anything standing on it.

Where it stands: 198 of 198 sim tests and 216 of 216 Unreal tests pass, and the self-driving runs pass 109 of 109 checks in the house-and-harvest run and 194 of 194 in the two-island run. The save is now schema v13, and every old save migrates forward; Kenneth's own save did on first launch. The push itself took three tries: the rebuilt ground's 21 MB of files kept timing out on slow wifi.

Days ten and eleven: an HD-2D camera, bugs and fish

2026-10-08 to 10-09 · tilt-shift camera, wave 14

First, a camera experiment that stuck: a low, long-lens HD-2D view in the spirit of Octopath Traveler, with a tilt-shift blur that makes the islands look like a miniature. Kenneth tuned the low version himself, and it's now the default camera. Then wave 14, straight from Kenneth's wish list: Animal Crossing-style bugs and fish that change with the seasons and with day and night, a net and a fishing rod with their own animations, and fixes for two creature problems he'd seen in play.

Honest status: Kenneth approved the list of 52 bugs and fish and tuned the camera, but the critter models, the tools, the tanks and the new animations are agent work waiting for his review, and the catch timings are first guesses that need a hands-on pass.

An HD-2D camera

Standard · HD-2D Strong · HD-2D Low
Three scenes on the islands, each shown three ways: on the left the standard over-the-shoulder camera with a clear sky; in the middle a high, steep view with heavy blur at the top and bottom of the frame like a miniature model; on the right a low, side-on view of the caretaker by the workshop, the cottage and a landing pad, with the foreground and the far distance softly blurred

From over the shoulder to a diorama

Kenneth tuned

Left to right: Standard, HD-2D Strong and HD-2D Low, as first shot before Kenneth tuned it. Kenneth: “I kind of like the strong one, but I also want one that's actually a lot more like lower angled… closer to what we have in Octopath”. So the dev panel got a live camera tuner, he dialled in Low himself and played on it for several sessions, and his version is now the default. In Low mode, anything that would block your view of the caretaker hides itself until you've passed. The player can switch modes in the phone's Settings.

Still rough: hidden objects pop out instead of fading, and tall grass can hide the caretaker's legs.

Wave 14: bugs and fish

Kenneth's ask: Animal Crossing style, by season, day and night
Six in-game frames: a pale green moth flapping in the grass; the caretaker at night on Kettle Island with glowing fireflies; the caretaker fishing at the edge of a turquoise pond; waiting for a bite; the caretaker holding a red and white koi over their head with a card reading You caught a Koi!; and holding up a big blue beetle with a card reading You caught a Solar Rhino Beetle!

Sneak, swing, cast, hold it up

pending review

Bugs: hold the button to sneak up, then swing the net; rarer bugs startle sooner. Fish are shadows in the water: cast, let the fish nibble, and press when it bites. The net and the rod each come in four tiers, and better tiers reach further or give you longer to react. Every catch ends the Animal Crossing way, held up to the camera with a little card. Each season has five day and five night bugs and fish, following the real calendar, with rain and snow specials. Kettle Island got a pond for it.

A sheet of 24 cute bug models on white: Meadow Butterfly, Lantern Bee, Ladybug, Garden Snail, Pill Bug, Hermit Crab, Woolly Caterpillar, Icecap Beetle, Skyglass Butterfly, Sky Dragonfly, Cicada, Grasshopper, Leaf Mantis, Moon Moth, Glowworm, Velvet Spider, Owl Moth, Ghost Crab, Firefly, Cricket, Orb Spider, Solar Rhino Beetle, Stag Beetle and Lamplight Katydid

24 bugs

Kenneth approved the roster

Kenneth approved the list of species; the models themselves are still waiting for his review. Each was drawn with nano-banana-pro, cut out with pixelcut and turned into 3D with Tripo H3.1.

A sheet of 24 cute fish and sea creature models on white, including a sand dab, sea bream, mackerel, rainbow trout, seahorse, blue tang, clownfish, ocean sunfish, koi, pufferfish, squid, lanternfish, river eel, octopus, glass shrimp, crayfish, catfish and a coral ray

24 fish

models pending review

River, pond and sea fish, plus a few friends that aren't strictly fish. Rarity sets what they're worth when shipped. A handful are weaker than the rest, like the glass shrimp and the river eel, and are flagged for Kenneth.

Four pale blue weather specials: a long-legged Puddle Strider, a fluffy Snowdrift Moth with snowflake wings, a spotted Ancient Lobefin and a sleek Glacier Pike

Rain and snow specials

Puddle Strider and Ancient Lobefin only show up in the rain; Snowdrift Moth and Glacier Pike only in the snow. They're worth the most.

Top row: an aquarium with a koi, a pufferfish, a sunfish and small tropical fish; a glass terrarium with a spider and beetles inside; a creature with a heart over its head after the caretaker gives it a Velvet Spider. Bottom row: the phone album's Critters tab showing caught bugs, caught fish with a koi detail card, and a silhouette for a fish not caught yet, each with Caught 14 / 52

Show them off, gift them, fill the Critterpedia

pending review

A catch can be shipped in the Supply Crate (Broadmeadow now has one too), gifted or fed to a creature, let go, or put in a craftable aquarium or terrarium. Each creature has a favourite species. The phone album has a new Critterpedia that fills in as you catch, with silhouettes and hints for the ones still out there.

Grey mannequin animation frames on a dark background: a bug net swing from wind-up to hit, a fishing rod cast, and a two-handed hold-up of a catch over the head

New caretaker animations

pending review

Keyed in Blender: the net swing, the rod cast, waiting for a bite, hooking and reeling, and the hold-up. The first rods read as logs in the game, so they were rebuilt slimmer (this sheet still shows the old ones).

Three grown creatures standing in the meadow, before on top and after below: a blue finned creature and a red winged one hold their arms well out from the body on top, and closer to their sides below

Creature fixes

pending review

Kenneth saw grown creatures with their arms straight out. It wasn't a T-pose: the shared clips hold the arms about 45 degrees out, which suits a round baby but not a long-armed grown body, so they now droop by 24 degrees (before on top, after below). Creatures also got stuck: now they only head for places they can fully reach, a stuck detector moves them on, and the Broadmeadow bridge reaches dry land on both sides. A 48-hour test run ended with nobody stuck.

One more thing: in Kenneth's first play of wave 14, the game closed on him when bugs and fish left the world mid-update. That was fixed the same day. Before that fix, everything passed: 147 of 147 sim tests, 149 of 149 Unreal tests and 185 of 185 end-to-end checks.

Days eight and nine: gathering, an outpost, a home base

2026-10-04 to 10-05 · waves 12 and 13, one playtest fix

Two waves, both straight from Kenneth's playtests. Wave 12 made gathering feel good: two kinds of wood, stones you can pick up, a scythe, a Stardew-style hotbar and bag, work animations, and run-down outpost buildings you can repair. Wave 13 gave the caretaker a home base on the starting island: a workshop with a locker, craftable chests, a crate that ships surplus to the company for Supply Vouchers, a trash can, and a polish pass on the ground and the big tree. Then one more playtest fix: you could get stuck holding an egg.

Honest status: Kenneth picked the building concepts, the icon style and the new story, but the animations, the home base, the voucher sign and the ground pass are agent work waiting for his next play.

Wave 12: gathering feels good

Kenneth's six playtest asks
Four in-game frames: the caretaker mid-chop on the beach, a mown swath in the meadow after a scythe swing, chopping a huge hardwood oak with a Stone Axe, and the open bag with 17 of 36 slots used

Wood, hardwood, stones, fiber

pending review

Logs come from any tree; hardwood comes from big trees and old stumps and needs a Stone Axe. Small rocks are loose stones you pick up by hand. The scythe mows a whole swath of meadow for fiber, and the grass grows back over five days. The hotbar works like Stardew Valley's: the selected tool decides what E does, and the bag grows from 12 to 24 to 36 slots.

A sheet of 38 painted item icons: branch, seed, part, log, stone, fiber, plank, rope, hardwood, fruits, fish, steak, six crystals, four tiers each of axe, pick, hammer and scythe, and two bags

38 hotbar icons

Kenneth picked the style

Every item and tool tier, drawn with nano-banana-pro in the style Kenneth chose from three tests, shown on dark and light slots.

Twelve frames of the caretaker on a beach drawing a tool, chopping, mining, hammering and swinging a scythe

Work animations

pending review

Keyed in Blender: drawing a tool, chopping, mining, hammering and scything for the caretaker, plus chop, hammer, sweep and carry for the creatures.

A grid of four solarpunk outpost buildings, each broken and repaired from front and back: a turf-roofed cottage, a glass-domed seed recoverer, a workshop with solar panels and a windmill, and a boat dock on stilts; below, the same buildings placed on Broadmeadow

The outpost buildings

Kenneth picked

Kenneth: “we want a solar punk vibe on this”, with a cottage, a seed recoverer as a late-game goal, a boat dock for getting between islands, and a workshop for tool upgrades. He picked a concept for each, and Tripo H3.1 multiview built all four in a broken and a repaired version with the same footprint. The bottom rows show them on Broadmeadow. The bunkhouse can already be mended with a hammer, with room for four creatures.

The story changed with them: nobody knows what happened to the last Prime. The outpost went dark six weeks ago, and everyone hoped it was just a bad relay.

Wave 13: the workshop is home base

from Kenneth's in-play notes · pending review
The workshop on Kettle Island, broken on the left and mended on the right with solar panels and a turning windmill; a workbench and a pale green locker stand in front

A workshop on the starting island

The workshop moved to Kettle Island, with the workbench and the Outpost Locker usable from day one. Mending it with a hammer opens the Brass and Solarpunk tool tiers and doubles the locker to 24 slots.

The caretaker beside a placed wooden storage chest in the grass near the workshop

Storage Chests

Craft one at the workbench from 10 logs and 4 fiber and place it anywhere: 24 slots, with a quick-stack button. Tools can be stored too, and if your axe is in the locker, the prompt says so.

Four views of the bag: a trash can beside the slots, a stack of logs held over the can, an Undo button after trashing, and a confirm card before trashing the Stone Axe

A trash can, with undo

Drop anything you don't want in the can, and take it back until you close the bag. Tools ask first, and story Parts can't be thrown away.

Supply Vouchers in game: the bag header showing 53, a morning toast reading Shipped overnight: 12 Log, 2 Rope, 7 Sweet Fruit, plus 53, the phone's Requests card with the voucher wallet, and the Supply Crate screen with a shipping manifest and estimated payout

Ship surplus for Supply Vouchers

glyph awaiting Kenneth

Put what you don't need in the Supply Crate at the landing beach. It ships overnight to the company that sent you, and the next morning you're paid in Supply Vouchers, the same wallet the daily requests pay into. Kenneth didn't want “tickets”, so the currency got its own sign: a V over an S that reads like a dollar. Six versions are below; he hasn't picked one yet.

Six candidate voucher signs combining a V and an S, each shown at four text sizes
Before and after pairs: on the right, path and beach edges are soft and wandering instead of hard lines, and the meadow grass varies in height and colour

Ground polish

Before on the left, after on the right. Kenneth found the paths too sharp and the beach edge too clean. Now edges wander and blend, the grass varies in height and colour with drier blades by the sand, it stays out of buildings, and it thins softly under trees instead of in hard circles. (The shed in the third pair is the old workshop ruin, which moved to Kettle.)

The big oak on Kettle Island from four angles: before, the trunk is split with gaps you can see the sky through; after, it is one solid trunk

The big tree, without holes

The starting island's big oak had see-through gaps in its trunk. The mesh is now watertight from every side.

The dev panel open beside the caretaker: tabs for Items, World, Build, Creatures, Travel and Save, with material and tool buttons and a voucher balance

A dev panel for playtesting

Ctrl+Cmd+D opens six tabs: give items and tools, set the sky and season, skip time, repair or break buildings, hatch and age creatures, teleport, and save or reload.

Six frames at a fallen log in tall grass: the Prime's hint to craft an axe, a hint to press 1, the axe selected, mid-swing, the log split with three logs gained, and a close-up of the cut faces and wedges

Fallen logs and one-time hints

Fallen logs split for a few logs with any axe and come back after three days. The first time you need a tool, the Prime tells you how to make it, and you get one reminder to press 1 to hold it.

Playtest fix: stuck holding an egg

2026-10-05
The caretaker in tall grass at dusk, with the messages You set the egg down. It will wait here; press E beside it to pick it up again

Set an egg down anywhere

one thing still open

With Kettle Island full, the incubator refused Kenneth's egg, there was no way to put it down, and carrying it to Broadmeadow stranded him there. Now G sets an egg down anywhere and it waits through saves and trips; eggs never block travel, since an egg isn't a resident until it hatches; and every refusal says how to get unstuck. Still open, and visible here: a set-down egg can disappear in tall grass.

Days five to seven: a real caretaker, creatures that grow up, crafting

2026-10-01 to 10-03 · waves 9, 10 and 11A, two playtest rounds, a trailer started

Three waves in three days. Wave 9 replaced the grey mannequin with a real caretaker: designed with Kenneth, built in 3D, skinned and animated, plus a title screen, baby coat variants and a grass fix. Wave 10 gave the creatures real grown-up bodies and some adult behaviour. Wave 11 is the big one: crafting, then decorating, then creatures that build the world themselves. Its first phase (tools, chopping, mining, a workbench) is merged. Two rounds of Kenneth's playtest notes were fixed in between.

Honest status: Kenneth chose the caretaker design and approved the creature bodies, but most of what's below is agent work still waiting for his review: the caretaker's model and animations, the title screen, the coats, the crafting concepts and the playtest fixes. The crafting meshes are placeholders.

Wave 9: the caretaker

from 80 drawings to a playable character
The 3D caretaker in game: turnaround views, a face close-up, walking, jogging, carrying an egg and a baby creature, petting, waving and the landing tuck

The Tech, in game

pending review

Tripo H3.1 multiview won a five-way bake-off. The model is skinned to Unreal's mannequin skeleton so the template's walking and running work, with 17 extra clips keyed in Blender.

A grid of eight caretaker characters redrawn in ten shape styles, from chibi to tall elegant to plush felt

Ten styles × eight characters

Kenneth picked

Eight caretaker concepts, each redrawn in ten shape styles with a note on how hard it would be to rig. Kenneth chose the Tall Elegant style and the Gadget Tech character.

Twelve baby creatures in tall grass, each with a different coat colour and marking

Baby coats

pending review

8 coats and 8 markings, read from each creature's genes and passed to its children. Peach, cream, honey, rose, sage, lilac, cocoa and ash, with stars, saddles, freckles, stripes and socks.

Before and after, seen from above: the old grass push flattened blades into a bright yellow ring; the new one bends them aside

Grass that bends, not flattens

Before, blades pushed by the player squashed into a flat bright ring. Now each blade bends at its root and keeps its length.

Wave 10: creatures grow up

adolescent and adult bodies for four lines · approved by Kenneth
Eight creature bodies in game. Top row, adolescents: Leaf, Fin, Wing and Stone. Bottom row, adults: Leaf, Fin, Wing and Stone. A small baby and the caretaker stand in the background

Leaf, Fin, Wing, Stone

approved

Top row: adolescents at 85 cm. Bottom row: adults at 120 cm. A baby stands behind each one for scale. Concepts were drawn with nano-banana-pro, built with Tripo H3.1 multiview (8 of 8 on the first try) and fitted to the baby's skeleton, so every existing animation plays on them. Adults can't be carried, but they can be shoved, and F asks a creature to follow you. Kenneth: “these look great”. He hasn't played with them yet.

Wave 11 Phase A: crafting

placeholder meshes in game · concepts waiting for Kenneth
Concept sheet: axe, pick, hammer and sickle in four tiers (Timber, Stone, Brass, Solarpunk), three wild tree species and an oak's growth stages

Tools and trees

pending review

Four tool tiers, from lashed timber to a vine-wrapped Solarpunk set, plus pine, birch and oak and the stages an oak grows through. The game logic is in; the art isn't yet.

What Phase A adds

  • An axe, pick, hammer and sickle in 4 tiers, with no durability to manage.
  • Chop wild trees and fruit trees. The Prime calls to warn you about the fruit trees, up to three times.
  • Mine rocks. Soft rocks give stone by hand, so you can build a first workbench before you own a pick.
  • Grass gives fiber, and cleared grass and branch piles grow back each day, so materials don't run out.
  • A workbench menu, the held tool in your hand and a materials list on the phone.
  • Save schema v6, with a migration tested on a real older save.

Next come decorating, then creatures doing jobs when you ask, then creatures that pass ideas to each other and form crews.

The caretaker before and after the skin weight fix: at idle the v1 spine curves into an S and v2 stands straight; jogging, v1's shoulder and hip bend badly and v2 is clean

Skin weights v2

pending review

Kenneth circled where the caretaker bent badly. v1 is on the left of each pair, v2 on the right: a straight spine at idle and a clean shoulder and hip when jogging. Shoulders still stretch a little with the arms overhead.

Playtest fixes

Kenneth's notes from 2026-10-03 · he hasn't replayed yet
Before and after: a rope bridge sitting low in the river now spans it from bank to bank; a planted tree buried to its canopy now stands on its trunk

Sunk bridges and trees

Generated meshes have their pivot in the middle, and the game placed them by it: bridges sat in the water and planted trees sat 2 m underground. They now sit on their banks and on the ground.

Broadmeadow from above, three minutes after landing: before, the creatures (coloured rings) are still clustered by the landing pad; after, they are spread across the meadow

Creatures that roam

Kenneth: the creatures “just stay right where the player lands”. Now they scatter on arrival, wander toward points of interest and meet at social spots. Earlier the same day they stood frozen in a row; now they stroll.

A trailer, in progress

stills from a work-in-progress cut · not released
Eighteen stills from the trailer cut: the logo over Broadmeadow, eggs on the beach, a baby in the grass, the caretaker with creatures, the slingshot launch, homes, a bridge, rain, snow and night, and the closing logo

Cut in HyperFrames from in-game shots

in progress

A console command flies the camera and records the shots offscreen, and the edit is built in HyperFrames, which makes video from HTML. The narration took three tries: the mentor's voice, then a movie-trailer announcer on two TTS engines, which Kenneth turned down. So an agent built a casting page with 25 voices across ElevenLabs v3, Gemini TTS and MiniMax. Kenneth wrote a first-person script for the player character, an apprentice caretaker who arrives to find the Prime gone, and picked one of 11 young voices reading it. The timing and the mix are still being reviewed.

Day four: the restyle

2026-09-30 · wave 7 overnight, wave 8 in the morning

The game played, but it looked like a greybox with a cel filter. Kenneth picked a set of AI concept paintings as the target look, and two art waves moved the real game toward them. Wave 7 (overnight, six lanes) added dense wind-swept grass, resculpted the islands into terraces with dirt lips, gave the look painterly shading, a painted sky and a warm night glow, and added footsteps that change with the surface. Wave 8 (five lanes, guided by Kenneth's research report on how Zelda-style games are rendered) added fog, cloud shadows, new trees and bushes, moving water, matte props and an overgrown nursery hub.

Honest status: Kenneth hasn't reviewed wave 8 yet, the caretaker is still the grey mannequin, and the concept frames below are AI paintings of where we're heading, not in-game shots.

Same camera, three days

the Kettle Island meadow, midday
Before the restyle: flat green ground with dotted grass tufts, a round tree and grey cliffs

Before

day three

Flat ground with a patterned grass texture and scattered tufts.

Wave 7: tall dense grass across a raised terrace with a dirt lip, the tree on the plateau

Wave 7

overnight

Dense instanced grass and a sculpted terrace with a dirt lip. The grass was bright and uniform.

Wave 8: softer grass with darker roots, a rebuilt rounded tree canopy, bushes on the terrace edge and haze on the cliffs

Wave 8

now

Grass roots share the ground's colour, a new canopy, bushes on the lip and height fog on the cliffs.

AI concept art target: rolling meadow with sandy paths, wildflowers, a fruit tree on a mossy ledge and cliffs behind

The target

AI concept art

The concept painting for this camera. Still ahead of us: the rolling paths, flowers and softer ledges.

Wave 8 in the engine

in-engine frames, no HUD · pending Kenneth's review
Aerial view of Kettle Island: terraced green plateaus, stepping-stone path, sandy beach and turquoise shallows

Kettle Island from above

The resculpted plateaus and the path in the valley. High views get a little lift so they don't go dull.

A Broadmeadow river with flow lines, dune grass on the banks and a broken plank bridge

River and bridge

Flow lines on the river, foam around the posts and grass along the banked edges.

Kettle Island at night from above: blue-green grass, moonlit sand and small warm lamp glows

Night, toned down

After the playtest, the lamp glow is half as strong and fades up close. Night grass is now deep blue-green.

The nursery hub overgrown with grass and ivy, sun shafts falling on five arched doors

The overgrown hub

A grass carpet, ivy on the walls, golden sun shafts and leaf shadows on the floor.

Close-up of a new tree: a rounded canopy of leaf clusters with one orange fruit, tall grass around the trunk

New trees

Canopies built from rounded leaf clusters that sway. Real fruit sits on the canopy instead of being painted on.

The beach and broken pier: waves washing onto wet sand, two supply crates in front

Beach and pier

Waves wash up and leave a wet band on the sand. Props are matte now and sit into the ground.

What didn't work, and what's left

  • Unreal's newest foliage tools (Nanite foliage, GPU PCG) are experimental on the Mac, with crash and floating-grass reports, so the grass is plain instanced meshes placed by our own code.
  • Wave 7 made the frame cost rise from about 6.5 to 9 ms. Wave 8 brought it back to about 8 ms at 1080p.
  • Wave 8's first review found regressions (darker overviews, a bare patch by the landing path, grey night grass). A fix pass sorted them before these shots.
  • A power cut hit mid-wave. Work lives in separate git worktrees, so only a few temporary scripts were lost.
  • Still to do: the race track is a bit neon from above, the canopies are rounder than the concept, and the caretaker is still a mannequin.

Day three: one big run

2026-09-29 · about 20 agent lanes in parallel, 08:45 to 18:00

One orchestrated run turned the starter island into a two-island game. The orchestrator wrote each wave's plan and a contract for the simulation, then dispatched lanes in parallel, each in its own git worktree: sim, narrative, maps, fal assets, UI, animation, gameplay, then race, homes, album, love & legacy, world & feel and audio. Every lane came back with tests and self-driving screenshot runs, and the orchestrator re-ran them before merging. The sim went from schema v2 to v5 over the day, each step with a migration so old saves still load.

Honest status: the caretaker is still the grey template mannequin. All the new art is waiting for Kenneth's review, and no human has listened to the new music yet. Kenneth is playing the build now.

Oblique aerial view of Broadmeadow, the main garden island: two rivers split it into four meadows joined by bridges, with dirt paths and cliffs

Broadmeadow, the main garden

playable

The second island. Two rivers split it into four areas, and each broken bridge takes 4 branches to repair. It has 9 fruit trees (sweet and sour), a request board that asks for fruit that grows on your island, a natural burrow for creatures to live in, and the race board.

The two-island MVP

restore, unlock, launch, travel

The path through it

  1. Restore Kettle Island: pull grass, gather branch piles, push rocks aside. Clears raise the island from Abandoned to Habitable, Healthy and Thriving, and make room for more creatures.
  2. The old caretaker's notes. Six notes around the island hide the four-digit nursery door code between them.
  3. The nursery hub. Behind the vault door, an underground room with a door for every island, locked until you reach that island. A biscuit tin on a shelf holds the part that repairs the broken incubator.
  4. Plant and set goals. Hand-fed fruit leaves a seed to plant. Any 3 of 8 goals loosen the giant slingshot on the beach.
  5. Launch. Carry one creature (G) into the pouch: pull back, a tumbling flight, and a squash-and-bounce landing on Broadmeadow.
  6. Fast travel. Once both doors are open, the phone's Travel app takes you through the hub.

A self-driving run (ct.TwoIslands) plays all of it in about 80 seconds: 87 of 87 checks.

In-game video call from Prime Rafi, a bearded mentor with goggles, on landing at Broadmeadow

Mentor calls from Prime Rafi

The phone rings at story moments (15 triggers), only when things are quiet: never twice within a minute and never over another panel. If several are due, you get one call with a short catch-up line.

The underground nursery hub: a round room with five arched doors, each with a sign

The nursery hub

Five doors: Kettle Island, the main garden (renamed by a test run here) and three locked ones for islands still to come.

The caretaker in the pouch of a giant rope-and-timber slingshot on the beach

The giant slingshot

A 3-second launch you can skip. A creature you're carrying tumbles along.

A repaired rope-and-plank bridge across a river on Broadmeadow

A repaired bridge

Repairing it removes the blocker and updates the navmesh, so creatures can cross too.

The in-game phone showing the Goals app with three of eight goals done

The phone

Creatures, Goals, Requests, Travel, Notes and Call Prime, all filled from the live sim. Album, Build and Settings came later in the day.

The first race

the Broadmeadow Loop · rank F · forgiving on purpose
Race HUD reading 3rd of 4: Tofu took a wrong turn at the hairpin, with two creatures showing question marks

Mistakes you can see

The sim decides the race. You watch it play back: wrong turns at hairpins (a “?” and a trot back), a stumble at the log, stopping to look at butterflies, a wide corner.

Race results card: Tofu came 2nd of 4, with what it learned and its race rank progress

What your creature learned

Results list what it learned from its mistakes (cornering, pacing, obstacles, course memory) and its progress to the next rank. Visiting rivals race in the same deterministic sim.

Homes, jobs and the album

creatures choose; you can only offer
A thatched hut with a sign reading Maple and Suki 2 of 2, two creatures and a heart by the door

Shelters and homes

Build a nest, a hut or a communal house anywhere valid. Carry a creature to one to offer it a home: trust, personality and friends decide whether it moves in.

A creature watering the ground with a watering can, a heart above its head

Jobs

On Broadmeadow, adolescents and older can be gatherers (branches to the stash box) or farmers (sweeter fruit that regrows faster). You suggest; they may say no.

The phone's Album app: a timeline of polaroid photos grouped by day

Album and photo mode

Big moments photograph themselves (a hatch, a first trip, a mended bridge). P opens photo mode with three filters and a caption.

Love and legacy

nothing is ever deleted: lives continue
Five creatures in a row, some with a gold halo, a dark wisp or a leaf sprig on the crown

Hero and Dark looks

How you raise them shows: a soft gold halo and warmer colours, or a shadow wisp and cooler ones, plus archetype accents (leaf sprig, fin ridge, wing nubs, stone freckles).

An elder creature sitting in a soft beam of light with gold motes rising, beside the caretaker

The elder ceremony

An elder in its final days glows warmer. If you choose to stay with it, it curls up in the light, becomes a glowing egg and hatches as Life II, keeping some of its memories.

Album Family tab: a creature's card with its lives, Life I and Life II, and its parents

The family tree

Two adults who like each other start courting (hearts, walks side by side). Bless them and an egg appears at their home. The Album's Family tab shows parents, lives and children.

World and feel

display only: none of it changes the sim
Kettle Island at night under a starry sky, the incubator glowing warmly in the distance

Day and night from your clock

The sun follows your local time and season. At night the light turns to moonlight with stars, and the incubators, nursery doors and shelters cast warm pools.

A thatched hut on Broadmeadow in winter, snow on the roof and the ground, snow falling

Seasons and weather

Spring blossom, autumn reds, winter frost and patchy cel snow, rain streaks. All from a second post-process pass, so the approved cel look underneath is untouched.

Top-down view of Kettle Island with a worn dirt trail through the grass beside the stepping stones

Worn paths

Where you and your creatures walk most, the grass wears to dirt, and it grows back over a few days. This is five simulated days of walking.

Music and ambience, all from fal

19 new audio files: eight music pieces (a day bed for each island, a night lullaby, the hub, the race and two stings, and the ceremony) from ElevenLabs Music and Google Lyria, four ambience loops (shore by day and night, meadow, hub hum) from Mirelo SFX, and seven sound effects. An audio director crossfades the beds at dusk, lowers the music during mentor calls and brings the shore up as you walk to the sea. The loops were cut and crossfaded by script and checked with measurements. Nobody has listened to them yet.

Also new: naming your islands on first arrival, vacation mode and volume controls in the phone's Settings.

New fal art

all pending Kenneth's review
Contact sheet of the day-2 kit: grass, branch piles, notes, keypad, slingshot, bridges, trees, hub doors and UI icons, concept beside 3D render

The MVP kit

pending review

16 props (restoration, notes, keypad, slingshot, bridges, hub doors, request board, trees), a hub floor texture and 14 UI icons. Concept on the left, Meshy 7.1 mesh on the right. Three weak meshes were redone.

Contact sheet of shelters: a twig nest, a thatched hut, a mushroom house, a stash box and a watering can, plus job icons

Homes and jobs kit

pending review

Nest, hut, communal house, stash box and watering can, plus job icons. The race kit (gate, flag posts, entry board, podium) was made the same way.

Three portrait candidates for the mentor Prime Rafi: goggles, sun hat and tinkerer

Prime Rafi candidates

Kenneth to pick

Three looks for the mentor, each with a desert variant. Goggles is in the game for now.

Still placeholder or unfinished

  • The caretaker is the grey template mannequin, including in the ceremony.
  • Love & legacy and world & feel were verified on an integration branch (62 of 62 Unreal tests, a 72-hour soak with no failures) and merged into main this evening; that is the build Kenneth is playing now.
  • Known issues in the build: a creature can run away while you carry it, taking a creature off Broadmeadow clears its job, the landing camera is a bit far, trees keep their painted fruit after harvest.
  • An open question for Kenneth: creatures left alone on the other island get neglect warnings, and one ran away within 7 in-game days in the soak. Is that the right pace?

Day two: in the engine

2026-09-28 · Unreal Engine 5.8 · greybox, not final art
In-engine screenshot: the baby Dumpling with a heart symbol beside the incubator, the caretaker stand-in and the vault door in the cave

Playable starter island

playable

Walk the island, pick fruit, hand-feed and pet the baby. The baby's behaviour comes from the simulation: it reads the sim's intent (wander, seek food, sleep, approach you) and acts it out on the navmesh, with a small emotion symbol overhead. The caretaker is still the template mannequin.

Wide in-engine view of the greybox island: grass, sand, dirt path, cube cliffs and a pier

The greybox island

About 80 by 60 m: grass, sand, a dirt path, the cave cliff (still cubes), the incubator, three fruit trees and a broken pier.

The sim runs inside Unreal

  • Loads the save (with a backup), then catches up on the time you were away.
  • Keeps a “While you were away” recap of what mattered.
  • Steps every 60 real seconds, from the wall clock, not the frame rate.
  • Autosaves every 5 minutes and on quit.
  • 11 of 11 Unreal automation tests (5 sim-in-engine, 6 gameplay), plus the 17 sim tests.

What the game is

design direction, not a feature list

You are the newly appointed Caretaker Prime of a neglected island sector. The previous caretaker is gone, the facilities are failing and the islands are overgrown. A caretaker from another sector helps over a patchy video link, but doesn't know your islands. A storm hit the sector some time ago, and you piece the rest together as you go.

You raise a small number of creatures, around 15 at most on the first real island. Genes, food, care, friendships, rivalries and how you treat them shape who each one becomes. The world runs on the real clock, including while the game is closed, and there is no game over from neglect. The goal is one companion with a personal history, not a collection.

01

Oddly alive

Creatures approach, choose, remember, teach, misbehave and make up, within rules you can read.

02

Agency with consequences

Praise, scold, feed, relocate. Context, trust, memory and who was watching change the outcome.

03

Time and continuity

Real clock and seasons, elderhood, reincarnation, descendants and a family album spanning years.

04

Restoration as play

Clear grass and rocks, find notes, repair hardware, plant trees, bring abandoned islands back.

05

A clean world view

Little HUD. Faces, behaviour and small emotion symbols carry the state; a phone holds the detail.

06

Systems first

The simulation is deterministic and saveable. AI helps make assets; it never decides what a creature does.

The return loop

Recap of what happened→ Walk the garden→ Notice needs→ Feed and care→ Harvest or plant→ Train, play, restore→ Leave it running

The first milestone we test against: after about a week of real time, do two creatures from staggered eggs feel different and produce stories you remember?

Art direction

cozy anime cel-shading, from an 8-page style guide

Rules every render is checked against

  1. Coloured contours. Lines are a darker shade of the fill they surround, never pure black.
  2. Flat fills, hard shadows. A base colour plus two or three hard-edged shadow steps. No gradients inside fills.
  3. Sunny light. Coastal sun from the upper left, a faint warm rim light, faces always lit.
  4. Hue-shifted shadows. Shadows go cooler and violet, not just darker grey.
  5. Chunky shapes. Rounded, readable silhouettes at gameplay distance. No spindly parts on babies.
  6. No texture noise. No fur strands, grain or bump noise. Fur is implied by silhouette tufts.
  7. One body plan. Every creature shares a biped rig: head, torso, two arms with usable hands, two legs.

Palette

Sampled from the style guide. These are the game's colours; this page stays monochrome so the art carries them.

Style anchors

test renders that prove the look reproduces before any real asset is made
Nursery cave concept with a locked stone door and the incubator

Nursery cave

Cave, locked vault door and incubator in one frame.

Prop sheet concept

Prop sheet

Rope, timber, faceted stone and rusty-cute company hardware.

Tileable ground texture test

Ground tile

Seam error at the wrap edges came out close to the interior baseline, so it tiles.

The look in Unreal

one post-process material for the whole game

How the cel-shading works

  1. Three tone bands. The light each pixel receives is split into lit, mid and dark, then multiplied back onto the flat base colour. Shadows lean violet.
  2. Coloured outlines. Drawn from depth, normal and stencil edges, on the nearer surface only, and coloured from the local fill instead of black.
  3. Warm rim light on characters. Characters are marked in the stencil buffer, which also keeps their faces out of the darkest band.
  4. Painted sky. An azure gradient with two-tone blob clouds.
  5. Off: Lumen, bloom, ambient occlusion, auto exposure. Fixed exposure keeps the bands predictable.
“like the cell shading”Kenneth, after playing, 2026-09-28
Look-dev scene: imported props and palette shapes under the cel-shading post-process

Look-dev scene

Imported props, the baby and palette swatches, re-shot after every change to the look.

Close-up of the baby creature under the cel-shading look

The baby under the look

In engine, with the character rim light and coloured outlines. Faces are kept out of the darkest band.

How we build it

one person, one orchestrator, many agents

Kenneth

Direction, taste, and every approval gate

Orchestrator · Claude Opus 5.5

Plans, dispatches, then re-runs every acceptance check itself

Planning & art direction

Fable / Opus subagents
  • Plan and architecture
  • Art bible and prompt blocks
  • Concepts, picks with written reasons

Engine code

Codex (GPT-6 Astra / Sol)
  • C++20 simulation core
  • Save schema and migrations
  • CMake + ctest loop

3D pipeline

Opus / Sonnet subagents
  • fal generation scripts
  • Headless Blender checks and fixes
  • FBX export for Unreal

Mechanical work

Sonnet subagents
  • Repo bootstrap, git LFS
  • Commits and pushes
  • Engine install checks
fal: art, 3D, textures, soundBlender (headless) Unreal Engine 5.8git + LFS, private repo

Systems first, AI for assets only

Creature behaviour, needs, time and saves are ordinary deterministic C++ with tests. No model call decides game state, and the game never needs a network call to run. fal generates the art, meshes, textures and sounds during development; those become normal files in the project.

Humans at the gates

Agents propose and check; Kenneth decides. The creature design was a hard stop: nothing went to 3D until he picked one. Every generated asset carries a manifest with the endpoint, prompt, references, file hashes, and an approved flag that only flips on his explicit decision, stored with his words.

The fal asset pipeline

every endpoint checked live before use

Creatures

Conceptnano-banana-pro/edit→ Turnaround4 views, A-pose→ Multi-image to 3DMeshy 7.1→ Rig + animationsMeshy multi-animation→ Blender checkbones, clips, holes→ UnrealFBX import

Caretaker and grown-up creatures (from wave 9)

Conceptnano-banana-pro/edit→ Locked multi-view sheet→ Multiview to 3DTripo H3.1→ Fit to a shared skeletonheadless Blender→ Unrealall clips reused

Props

2 conceptsnano-banana-pro/edit→ Agent picks onereason recorded→ Image to 3DMeshy 7.1→ Blender checktris, bounds, scale

Textures and sound

Tiling albedoz-image turbo tiling→ 2x2 seam check→ Normal mappatina · SFXElevenLabs SFX v2 AmbienceMirelo SFX 1.6

Ground textures, tiled 2x2

5 of 5 done

Tiling a texture 2x2 makes seams obvious. Ideogram tiling kept stalling, so all five came from z-image turbo tiling, with patina normal maps.

Grass texture tiled 2x2
grass
Grass with weeds texture tiled 2x2
grass + weeds
Sand texture tiled 2x2
sand
Dirt path texture tiled 2x2
dirt path
Rock texture tiled 2x2
rock

Starter sound set

Footsteps on grass, grass pull, pickup whoosh, fruit crunch, egg crack, hatch chime, happy chirp, hungry whine, phone ping, and a looping island ambience: 15 files, since some sounds have variants. All are imported into Unreal; pickup, crunch, chirp and whine already play in the greybox.

Models we've used

every generation model so far (all run on fal), plus the agents

Every generated asset keeps a manifest with the exact endpoint, prompt and references, so this list comes straight from those files. Some models won a bake-off and became the default; others were tried and dropped, and they're listed too.

The creature

one neutral baby that every lineage grows from

The first baby has to be archetype-neutral: tan and cream, no leaves, fins, feathers or crystals. What it grows into comes from genes and care. The art agent drew four candidates, each with a hero render and a turnaround for 3D. Then the build paused for a human pick.

“for creatures let go with C”Kenneth, 2026-09-27
Dumpling front view
front
Dumpling three-quarter view
three-quarter
Dumpling side view
side
Dumpling back view
back

Dumpling turnaround

The four A-pose views fed to Meshy's multi-image-to-3D. Consistency across views matters more than any single drawing.

Dumpling 3D v1 review sheet: concept beside 3D front, side, back and walk frames

3D v1: Meshy 7.1, 24-bone rig, 12 clips

rejected

Concept on the left, the rigged mesh and walk-cycle frames on the right. The shape came through well. The colour reads browner and greyer than the concept because Meshy bakes shading into the texture.

An honest note on v1, and what v2 fixed

The v1 skin weights from the auto-rig deformed badly, and Kenneth rejected it: the head deformed as it turned and the arms warped the body. Measuring it confirmed him. Head and neck influence was spread across the face, arm bones pulled on the belly, and several joints sat outside the mesh; one knee was above the hip.

v2 re-placed the joints inside the body and re-skinned the mesh by region: a rigid head, with narrow blend bands at the neck, armpits and hips. Bone orientations are unchanged, so the same 12 clips still apply. Measured head distortion went from up to 270 mm to 0, and belly leak on the wave clip from 33 mm to 0. The texture was colour-matched to the concept.

One more bug surfaced in Unreal: with any animation applied, the baby rendered about 1 cm tall. The animation files carried their metre-to-centimetre scale differently from the mesh. Importing the animations at x100 on the root bone fixed it. Still to do: the generic clips don't suit a round body (the wave is hidden, the belly creases, the feet dip), so custom clips are next.

Skin weights comparison on the wave and walk clips: v1 on the left, v2 on the right

Weights: v1 (left) vs v2 (right)

v2 done

Same skeleton, same clips. Watch the head and belly in the wave frames. Full sheet with all four clips.

Texture comparison: concept, v1 texture, v2 texture

Texture: concept, v1, v2

v2 done

v2 pulls the tan and cream back toward the concept and flattens the baked shading, so the toon shader can do the shading.

Prop kit

concept vs Meshy 3D render, 13 props

Simulation core

CaretakerSim · C++20 · no engine headers

Deterministic

All state is integers: needs and stats in fixed-point hundredths, times in Unix seconds. No floating-point values are saved. Randomness is a hash of world seed, subsystem, entity, tick and draw number, so one creature's luck can't shift another's, and a replay with the same seed gives the same bytes.

Offline catch-up

The world ticks every 60 seconds. When you come back, the first 24 hours away are replayed minute by minute; after that it steps hourly, with harm damped the longer you were gone. Catch-up is capped at 60 days. Moving the clock backwards changes nothing. Vacation mode slows ageing and holds needs above a floor.

TestWhat it proves

ctest · the first 17 cases, from day one. By 2026-09-29 the sim is at schema v5 with 70 of 70 cases passing, and Unreal runs 62 automation tests on top.

First playtest

what Kenneth flagged, 2026-09-28
FlagWhat we're doingStatus

This is the review loop: Kenneth plays, flags what's off, and the agents fix it. Nothing is marked done until he says so.

Engine setup lessons

UE 5.8 on a Mac, things that cost us time

1 · The Epic launcher's App Translocation loop

macOS runs quarantined apps from a randomized, read-only location (App Translocation). The launcher tried to update itself there, couldn't, and restarted into the same update. Clearing the quarantine attribute let it run from /Applications and finish updating.

xattr -dr com.apple.quarantine "/Applications/Epic Games Launcher.app"

2 · Xcode 26+ ships without the Metal compiler

Since Xcode 26 the Metal toolchain is a separate download. Without it, shader compiles fail with cannot execute tool 'metal' due to missing Metal Toolchain. One-time fix per machine:

xcodebuild -downloadComponent MetalToolchain
xcrun metal --version

3 · UE 5.8 has an MCP plugin

Unreal 5.8 includes Epic's experimental ModelContextProtocol plugin, which lets agents talk to the editor. It's enabled in the project (editor only), next to the Python scripting plugin, and we verified it answers (HTTP on port 8000 by default). Most editor automation still runs as headless Python. This UE version's SDK config also accepts Xcode 27, so C++ builds work on a current toolchain.

4 · Renaming the template project

UE 5.8 ignored ActiveGameNameRedirects when we renamed the ThirdPerson template's packages and classes. [CoreRedirects] entries worked. Copying TP_ThirdPerson also misses the shared template packs (Characters, Input, LevelPrototyping), so the mannequin and input assets had to be added by hand.

5 · Headless test runs that silently skip the tests

-ExecCmds="Automation RunTests ...; Quit" quits before the tests run. Use -TestExit so the editor exits when the test queue is done, and check the test count in the log.

6 · A game window that never appears

Launching -game through the UnrealEditor-Cmd binary plays sound but shows no window on macOS. The launcher now starts the game through UnrealEditor.app.

7 · Network outages mid-generation

Two DNS outages killed running agents. Because every fal job is logged with its request_id, the finished results were fetched afterwards rather than regenerated.

Dev log

newest first

What's next

target: a playable cel-shaded starter island