🍄 Nintendo2020Nintendo EPDVERY HARDAnimal Crossing: New Horizons rebuild deck
VERY HARD
An island that derives every state from a timestamp rather than a timer is a weekend; the reason anyone cared about a talking duck is four hundred villagers of hand-written dialogue across eight personality templates.
You will get a good prototype. The product is what comes after.
The agent will reach for setInterval and a save-on-tick model, and it will work beautifully right up until you close the tab, at which point the island quietly stops existing. Insist on derive-from-timestamp and then grep the first draft for hidden timers, because there will be one. What no prompt hands you is the writing — eight personality templates across four hundred villagers is a very large pile of authored dialogue, and it is the only reason anyone cared about a talking duck.
- Difficulty
- VERY HARD · 4 of 5
- First playable
- A project
- The original
- 250 team-years
- Released
- 2020 · Nintendo
- Genre
- Life Simulation
Build a real-time island life sim. Single page, Canvas 2D isometric, one island, about a week of content. Requirements: - The load-bearing rule: no game state is ever stored as a running timer. Everything derives from Date.now() and a per-island seed, evaluated lazily at the moment you look at it. Shop stock, weather, which trees have fruit, which rock pays out money, villager positions and market prices are all pure functions of (seed, dayIndex, hour). Persist only the seed, the player's inventory, and a set of consumed-event keys. Close the tab for three days and the island must come back exactly three days older — fruit regrown, stock rotated — with no catch-up loop and nothing double-counted. - Time-of-day lighting driven by the wall clock: dawn, noon, dusk, night, applied as a colour multiplier over the whole canvas. - Gathering verbs with cooldowns measured in days, not seconds. Shake trees. Hit rocks, eight payouts if you land them before the timer expires. Dig four randomised fossil spots per day. Fish that only exist in certain hours. - An interest-free debt you take on voluntarily, which upgrades your house and immediately offers you a larger one. No fail state, ever, anywhere. - Grid-snapped furniture placement with a translucent ghost preview, rotation, and no overlap. - Six villagers who wander on daily schedules and remember the last thing you gave them. Definition of done: I set my system clock forward two days, reload, and the island has aged exactly two days with nothing counted twice.
- Around 400 villagers on eight personality templates, with enough hand-written dialogue that people genuinely grieved when one moved out
- Several thousand furniture items sitting behind a colour-and-variant matrix, all modelled and catalogued
- A full year of real seasonal events, hemisphere-aware, each with its own art and its own items
- Visiting other people's islands, which is the entire reason this became a social object in March 2020
The Stalk Market — a weekly price series drawn from one of four hidden patterns you have to identify from partial data.
It is a complete minigame made of one array and a coin flip, and it produces real tension twice a day because the player is doing inference rather than clicking. Drop it into anything with a currency: a trading post, a crafting sim, a management game. The fun is living inside the uncertainty, not the arithmetic.
ScopeAn evening— build just this, not the game
Build a single-file HTML page, Canvas 2D, showing a hidden-pattern price series. Requirements: - One tradeable good. On Sunday the player buys at a price between 90 and 110. Monday to Saturday there are twelve selling prices, morning and afternoon. - On Sunday, secretly pick one of four patterns: fluctuating (wobbles around the buy price), decreasing (a steady slide to nothing), large spike (three days of decline then one price at 2-6x), small spike (decline then a modest 1.4-2x bump). Randomise the exact values and the spike day within each pattern. - Never name the pattern. The player sees only the prices revealed so far, on a line chart, and must decide each half-day whether to sell the lot. - After selling, reveal which pattern it was and what the best possible sale would have been. - Give the player a notebook: they tag the current week with a guess, and you track their accuracy across weeks. Definition of done: by week four I am selling on a hunch from three data points, and I am beating chance.
Not a clone — Animal Crossing: New Horizons re-themed and cut down to something you can finish. The angle is the important reel: it is what turns a project into a weekend. 5,880 ways to land.
Verdant From Above
Animal Crossing: New Horizons, but a management sim of the same world, set in a solarpunk city. Rendered in flat vector minimalism.
Build a browser game called "Verdant From Above". The pitch in one line: a life simulation in the spirit of Animal Crossing: New Horizons, but a management sim of the same world, set in a solarpunk city. WHAT THIS IS Take the SHAPE of Animal Crossing: New Horizons — its core loop, and whatever makes that loop good — and rebuild it as your own game in a different world at a smaller scope. Use your own names, art and audio, which you want anyway: a reskin of somebody else's game is less interesting than a new one that works the same way. THE ANGLE — this is the important constraint, honour it above everything else A management sim of the same world. The player never controls a character — they set policy and watch agents with visible needs succeed or fail at it. This is what makes the project finishable. If a decision would push the scope back towards the original's, take the smaller option every time. THE THEME A solarpunk city. Abundance rather than scarcity, and conflict that comes from competing goods rather than from enemies. The theme is not a coat of paint. Let it change what the mechanics mean — a reload, a health pack and a locked door should all be things that make sense in this world and nowhere else. LOOK Flat vector minimalism. Pure geometry, no textures, three colours plus white. All feedback carried by motion and scale rather than detail. REQUIREMENTS - Runs in a browser with no build step. Canvas 2D unless the angle genuinely requires 3D, in which case three.js. - Fixed-timestep update loop with interpolated rendering, so it behaves the same at 60Hz and 144Hz. - Every tuning constant in one CONFIG object at the top, exposed as live sliders in a debug panel. You will find the feel by dragging those, not by prompting. - All content — levels, entities, balance numbers — in JSON or plain data files, never inline in the logic. - Audio generated with the Web Audio API rather than asset files. - Respect prefers-reduced-motion: keep the fades, drop the shake and the parallax. BUILD ORDER 1. The core loop with placeholder rectangles, at the reduced scope the angle demands. No theme, no art, no audio. Make it fun as rectangles first. 2. The angle's consequences. Cutting to bots, or to turn-based, or to one level changes the design rather than just shrinking it — find out how and rewrite step 1. 3. The theme, as content and data. 4. The look, applied last as a rendering layer over a game that already works. Start by writing a one-page plan: the core loop, what the angle removes and what that frees you to do properly, and what you are deliberately leaving out. Wait for me to approve it before writing code.
Half the time one of these already does what you wanted, and the other half it saves you a week of solving a problem someone documented in 1997.
One count per game. No account — it is tied to a salted hash of your IP, which is not stored in a form anyone can reverse. Every build adds 250 team-years to the counter on the homepage.
Then try these
Questions
How hard is Animal Crossing: New Horizons to rebuild with an AI agent?
Yes — every game is buildable at some scope. The question is how hard, and Animal Crossing: New Horizons is VERY HARD (4 of 5). You will get a good prototype. The product is what comes after. An island that derives every state from a timestamp rather than a timer is a weekend; the reason anyone cared about a talking duck is four hundred villagers of hand-written dialogue across eight personality templates. Reckon on a project to something you can actually play — not to something that matches the 250 team-years Nintendo EPD spent.
What makes Animal Crossing: New Horizons hard to rebuild?
An island that derives every state from a timestamp rather than a timer is a weekend; the reason anyone cared about a talking duck is four hundred villagers of hand-written dialogue across eight personality templates. That is why it sits at VERY HARD rather than a tier either side of it. If you want the idea without the project, the transferable part is the stalk market — a weekly price series drawn from one of four hidden patterns you have to identify from partial data. — an evening of work.
How long does it take to build a Animal Crossing: New Horizons clone?
Wrong question, and it is worth saying why. Nobody rebuilds Animal Crossing: New Horizons — the original took Nintendo EPD on the order of 250 team-years, released in 2020 on Nintendo. What you can do is reach something playable and genuinely yours in about a project, and then keep going for as long as it stays interesting. Any figure that claims otherwise is measuring a prototype and calling it a game.
What do I lose by building my own Animal Crossing: New Horizons?
Around 400 villagers on eight personality templates, with enough hand-written dialogue that people genuinely grieved when one moved out. Several thousand furniture items sitting behind a colour-and-variant matrix, all modelled and catalogued. A full year of real seasonal events, hemisphere-aware, each with its own art and its own items. Those are the parts a prompt will not hand you.
Which AI coding agent should I use to build it?
Any of Claude Code, Codex or Cursor will handle this prompt. Paste it as your first message, let the agent scaffold the project, then iterate on feel — the second, third and tenth prompts are where a game actually gets good. Work in an empty folder or a fresh git branch so you can throw it away cheaply.
One email when new games go on the list. No other reason to email you, ever.