👾 Arcade1981NintendoFIDDLYDonkey Kong rebuild deck
FIDDLY
Sloped girders: ask for tile collision and your carpenter stutters and micro-falls down every incline forever, derive the foot position from the segment instead and it is solid on the first pass.
You will get it, but one specific system will fight you.
Slopes are where this falls apart. Ask for tile collision and you get a player that stutters and micro-falls down every incline, which no amount of prompting after the fact will fully fix. Derive the foot position from the segment instead and the movement is solid in one pass. The barrel ladder roll is worth reviewing carefully too, because a model will happily make it deterministic and then the stage is a memorisation test rather than a game.
- Difficulty
- FIDDLY · 2 of 5
- First playable
- A weekend
- The original
- 3 team-years
- Released
- 1981 · Arcade
- Genre
- Arcade Platformer
Build a single-screen arcade platformer set on sloped girders as one self-contained HTML file. Canvas 2D, Web Audio, no build step. Requirements: - Four stage layouts in stages.json: sloping girders with rolling barrels, a conveyor stage, an elevator stage, and a rivet-removal stage. Tune the girder stage to completion before touching the other three. - Ground height comes from the girder's slope, not from a physics solver. Each girder is a line segment and the player's feet snap to that segment's y at their current x. Walking down a slope must never leave the player airborne for a single frame. - The jump is a fixed parabola. Horizontal velocity is frozen at takeoff, there is no mid-air steering, and the arc covers about four cells forward and 1.4 cells up in roughly 500ms. - Barrels roll downhill, accelerating with the gradient. When a barrel's centre passes within 3px of a ladder top, roll a weighted die: 25% chance it descends, otherwise it rolls on. That single check is the whole difficulty of the stage and the only source of variety, so put the weight in the JSON. - Ladders: hold up to mount, vertical movement only, and a full cell of climb required before release at the top. - Points for jumping a barrel, a hammer power-up on a 10-second timer, a bonus counter that drains. Definition of done: I can clear the girder stage without dying, and barrels sometimes take the ladders and sometimes do not.
- Nintendo's characters, which are approximately the entire reason anyone remembers this
- The between-stage cutscenes, and hand-placed layouts that make each stage a puzzle rather than a level
- The vertical 4:3 monitor and a joystick stiff enough to make a jump feel deliberate
- A verified high-score scene with feuds, documentaries and disputed tapes
Committed jump arc with no air control
A jump you cannot steer in mid-air moves the decision to before takeoff, which is the whole reason arcade platformers feel tense and modern ones feel generous. It also makes level design tractable: the arc is a fixed shape, so every gap is either exactly reachable or deliberately not.
ScopeAn evening— build just this, not the game
Build a jump-model comparison toy. Single self-contained HTML file, Canvas 2D, no dependencies, no build step. - A character on flat ground with a few floating ledges, running left and right at a constant speed. - Three jump models switchable live on keys 1 to 3, all reaching the same apex and the same distance: committed, where horizontal velocity is frozen at takeoff, no air steering exists, and the arc is a fixed 500ms parabola; full air control, where horizontal velocity is settable every frame in flight; and variable height, where releasing the button early cuts the rise. - Draw the predicted arc as a ghost from the moment of takeoff, and leave the last five arcs on screen as fading trails. - One ledge placed exactly at the committed model's landing point, and one a quarter-cell beyond it. - Corner readout: apex height, air time, distance travelled. Definition of done: under the committed model the ledge a quarter-cell beyond the arc is unreachable whatever I press in mid-air, and under full air control it is trivial.
Not a clone — Donkey Kong 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 Turn Order
Donkey Kong, but turn-based instead of real-time, set in a solarpunk city. Rendered in silhouette against one light.
Build a browser game called "Verdant Turn Order". The pitch in one line: a arcade platformer in the spirit of Donkey Kong, but turn-based instead of real-time, set in a solarpunk city. WHAT THIS IS Take the SHAPE of Donkey Kong — 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 Turn-based instead of real-time. Time only advances when the player acts. Removes every timing, netcode and animation-blending problem and turns reflexes into decisions. 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 Silhouette against one light. Everything renders pure black against a lit background, with depth from four parallax layers of increasing blur, grain and a heavy vignette. 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 3 team-years to the counter on the homepage.
Then try these
Questions
How hard is Donkey Kong to rebuild with an AI agent?
Yes — every game is buildable at some scope. The question is how hard, and Donkey Kong is FIDDLY (2 of 5). You will get it, but one specific system will fight you. Sloped girders: ask for tile collision and your carpenter stutters and micro-falls down every incline forever, derive the foot position from the segment instead and it is solid on the first pass. Reckon on a weekend to something you can actually play — not to something that matches the 3 team-years Nintendo spent.
What makes Donkey Kong hard to rebuild?
Sloped girders: ask for tile collision and your carpenter stutters and micro-falls down every incline forever, derive the foot position from the segment instead and it is solid on the first pass. 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 committed jump arc with no air control — an evening of work.
How long does it take to build a Donkey Kong clone?
Wrong question, and it is worth saying why. Nobody rebuilds Donkey Kong — the original took Nintendo on the order of 3 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 Donkey Kong?
Nintendo's characters, which are approximately the entire reason anyone remembers this. The between-stage cutscenes, and hand-placed layouts that make each stage a puzzle rather than a level. The vertical 4:3 monitor and a joystick stiff enough to make a jump feel deliberate. 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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