👾 Arcade1981Atari, Inc.FIDDLYCentipede rebuild deck
FIDDLY
The mushroom field is persistent state that every other creature exists to manipulate, so if a model renders mushrooms as scenery you have silently deleted the flea, the scorpion and the segment split in one go.
You will get it, but one specific system will fight you.
The mushroom field is the game's memory and every other creature exists to manipulate it. Get the split right and the difficulty tunes itself. Models tend to make mushrooms purely decorative, which quietly removes the flea and scorpion's entire reason to exist, so check that first. Mouse input is the honest substitute for a trackball; do not add acceleration curves trying to fake the weight.
- Difficulty
- FIDDLY · 2 of 5
- First playable
- A weekend
- The original
- 2 team-years
- Released
- 1981 · Arcade
- Genre
- Arcade Shooter
Build a vertical arcade shooter in which a segmented crawler descends through a field of mushrooms. One self-contained HTML file, Canvas 2D, Web Audio, no dependencies. Requirements: - A 30x30 cell playfield. The player moves freely within the bottom four rows only, driven by mouse position or arrow keys, firing rapidly with one shot in flight at a time. - The crawler is a list of segments trailing a head. On striking a mushroom or a side wall it reverses horizontally and drops exactly one row. - Shooting a body segment turns that cell into a mushroom AND splits the body: the segment behind the hit becomes an independent head with its own direction. Shooting the head leaves the remaining tail to grow a new head. Implement and verify this split before writing a single line of cosmetic code, because it is the game. - Mushrooms persist across lives, take four hits to destroy, and half-regenerate between lives. - Escalation, all of it driven by the mushroom field: a spider bounces diagonally through the player zone eating mushrooms, scoring higher the closer you kill it. A flea drops vertically planting mushrooms whenever the count in the player zone falls below five. A scorpion crosses the upper field poisoning mushrooms, and a crawler touching a poisoned one dives straight down. - Speeds, spawn thresholds and wave composition in waves.json. Definition of done: one shot into the middle of a full-length crawler leaves me fighting two crawlers moving independently.
- The trackball. A mouse gets close, but the flywheel spin of a real one is not something you can emulate
- Atari's name and the phosphor bloom those saturated colours were designed around
- The two-player alternating cabinet, and the queue of people waiting behind you
Enemies that split where you hit them
One enemy that becomes two exactly where you shot it means the player's aim decides how the fight escalates, so hitting the middle and hitting the tail are different decisions and you never had to write a difficulty setting. It drops into anything built as a chain: worms, convoys, patrol lines, boss limbs.
ScopeA weekend— build just this, not the game
Build a splitting-chain toy. Single self-contained HTML file, Canvas 2D, no dependencies, no build step. - A chain of twelve segments following a head. Segments read positions out of the head's shared path history at fixed spacing — a ring buffer of past positions — not per-segment springs and not follow-the-leader copying. - Clicking a segment destroys it and splits the chain in two. Each half becomes an independent chain with its own head, its own direction, and a path history sliced from the parent's, so neither half snaps or teleports on the frame it is created. - Handle the awkward cases explicitly and list them in the interface as passing or failing: hitting the head, hitting the tail, a chain of length one, a chain of length two split at the join, and two hits landing in the same frame. - Give every chain an id and a colour and label its length on screen. Chains steer independently and collide with the walls and each other. Definition of done: one hit into the middle of a twelve-segment chain leaves two six-segment chains moving independently, with no visible snap on the frame of the split.
Not a clone — Centipede 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.
Fathomless Same Sofa
Centipede, but local split-screen instead of online, set in cosmic horror. Rendered in hand-drawn ink on paper.
Build a browser game called "Fathomless Same Sofa". The pitch in one line: a arcade shooter in the spirit of Centipede, but local split-screen instead of online, set in cosmic horror. WHAT THIS IS Take the SHAPE of Centipede — 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 Local split-screen instead of online. Two players, one keyboard or two gamepads, one screen. All the multiplayer fun, none of the distributed systems. 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 Cosmic horror. The threat should be mostly absent. Information the player uncovers should make things worse rather than better. 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 Hand-drawn ink on paper. Rough stroked outlines with per-frame jitter so lines boil, a paper-grain texture over everything, and ink-bleed on impacts. 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 2 team-years to the counter on the homepage.
Then try these
Questions
How hard is Centipede to rebuild with an AI agent?
Yes — every game is buildable at some scope. The question is how hard, and Centipede is FIDDLY (2 of 5). You will get it, but one specific system will fight you. The mushroom field is persistent state that every other creature exists to manipulate, so if a model renders mushrooms as scenery you have silently deleted the flea, the scorpion and the segment split in one go. Reckon on a weekend to something you can actually play — not to something that matches the 2 team-years Atari, Inc. spent.
What makes Centipede hard to rebuild?
The mushroom field is persistent state that every other creature exists to manipulate, so if a model renders mushrooms as scenery you have silently deleted the flea, the scorpion and the segment split in one go. That is why it sits at FIDDLY rather than a tier either side of it. If you want the idea without the project, the transferable part is enemies that split where you hit them — a weekend of work.
How long does it take to build a Centipede clone?
Wrong question, and it is worth saying why. Nobody rebuilds Centipede — the original took Atari, Inc. on the order of 2 team-years, released in 1981 on Arcade. What you can do is reach something playable and genuinely yours in about a weekend, 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 Centipede?
The trackball. A mouse gets close, but the flywheel spin of a real one is not something you can emulate. Atari's name and the phosphor bloom those saturated colours were designed around. The two-player alternating cabinet, and the queue of people waiting behind you. 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.
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