🍄 Nintendo1987KonamiHARDContra rebuild deck
HARD
The run-and-gun loop is right on day one, which is the trap, because everything after that is enemy placement: eight stages of playing your own build until each screen has exactly one fair answer.
You will get the loop working. Then the real work starts.
The loop lands quickly and feels good almost immediately, which is misleading, because what you are missing is eight stages of level design where the enemy placement is the entire craft. Agents also default to giving you three hit points, apparently out of kindness, and it ruins the pacing outright. Weapons as JSON is worth insisting on early, since the spread gun's bullet cap is the one number you will end up adjusting a dozen times. The pseudo-3D corridors are a separate project and you should treat them as one. Dates, since they get muddled: the arcade original is February 1987, the NES version everyone actually means is February 1988, and the stage layouts differ between them.
- Difficulty
- HARD · 3 of 5
- First playable
- A project
- The original
- 4 team-years
- Released
- 1987 · Nintendo
- Genre
- Run And Gun
Build a horizontally scrolling run-and-gun platformer as a single self-contained HTML file. Canvas 2D, Web Audio, tilemap and enemy placements in JSON, no build step. Requirements: - Eight-direction aiming that does not interrupt the run. Neutral fires forward, up fires up, diagonals fire diagonally, and crouching fires along the floor. - The camera scrolls forward only and never rewinds. The player is hard-clamped at the left edge. Enemy spawners are markers placed on the tilemap keyed to camera x, firing once as the camera crosses them. - One hit kills. On death you drop your weapon, respawn in place after 40 frames with 90 frames of flashing invulnerability, and the camera does not move for any of it. This rule is where all the tension lives, so do not add a health bar, do not add a checkpoint rewind, and do not soften the weapon loss. - Weapons as data: default rifle, spread firing five bullets at 12-degree offsets with a 12-bullet cap, laser firing one long piercing beam that replaces the previous shot, and fire whose bullets travel a sine spiral. Pickups drift across the screen inside a capsule. - Jumping is a forward tumble with full air control, plus down-and-jump to drop through one-way platforms. - One boss: an armoured wall with a weak point that opens only between attack cycles. Definition of done: I can pick up the spread gun, die to a stray bullet, and be fighting again on the same screen with the plain rifle two seconds later.
- Eight stages of hand-built level design, which is most of what the game actually is
- The pseudo-3D base corridors, effectively a second engine wearing the same clothes
- Konami's name, the sprite art, and the cultural weight of a certain thirty-life cheat
- Couch co-op with someone who keeps stealing your spread gun
One-hit death that costs your weapon, not progress
Agents hand you three hit points out of kindness and quietly delete all the tension. Punishing death by taking your power rather than your position keeps the pressure at maximum without ever making a player replay ground they already earned, and it turns an ordinary pickup into something worth protecting.
ScopeA weekend— build just this, not the game
Build a death-cost prototype as a single self-contained HTML file. Canvas 2D, Web Audio, no build step. - One flat arena, a player who runs and shoots, and enemies entering from both sides firing slow, clearly visible projectiles. - One hit kills. No health bar, no shield, no regenerating anything. - On death: the player drops the current weapon as a pickup exactly where they stood, respawns at that same position after 40 frames, and gets 90 frames of flashing invulnerability. The camera does not move, enemies do not reset, no progress is rolled back. Power is the only thing lost. - Three weapons defined in a JSON block: a starter firing one bullet, a spread firing five at 12-degree offsets with a bullet cap, and a beam that pierces and replaces its own previous shot. Pickups drift across the arena inside a capsule. - A stat line: seconds since last death, current weapon, deaths this run. Definition of done: I die at full power and I am shooting again in the same spot two seconds later with the starter weapon, the dropped one still lying there, tempting me.
Not a clone — Contra 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. 24,360 ways to land.
Brasswork Turn Order
Contra, but turn-based instead of real-time, set in steampunk. Rendered in blueprint technical drawing.
Build a browser game called "Brasswork Turn Order". The pitch in one line: a run and gun in the spirit of Contra, but turn-based instead of real-time, set in steampunk. WHAT THIS IS Take the SHAPE of Contra — 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 Steampunk. Visible mechanism everywhere. Anything that moves does so because a gear you can see is turning it, and pressure is a resource. 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 Blueprint technical drawing. White line-work on a blue ground, dimension lines and callout labels on live objects, and a grid that is diegetic rather than decorative. 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 4 team-years to the counter on the homepage.
Then try these
Questions
How hard is Contra to rebuild with an AI agent?
Yes — every game is buildable at some scope. The question is how hard, and Contra is HARD (3 of 5). You will get the loop working. Then the real work starts. The run-and-gun loop is right on day one, which is the trap, because everything after that is enemy placement: eight stages of playing your own build until each screen has exactly one fair answer. Reckon on a project to something you can actually play — not to something that matches the 4 team-years Konami spent.
What makes Contra hard to rebuild?
The run-and-gun loop is right on day one, which is the trap, because everything after that is enemy placement: eight stages of playing your own build until each screen has exactly one fair answer. That is why it sits at HARD rather than a tier either side of it. If you want the idea without the project, the transferable part is one-hit death that costs your weapon, not progress — a weekend of work.
How long does it take to build a Contra clone?
Wrong question, and it is worth saying why. Nobody rebuilds Contra — the original took Konami on the order of 4 team-years, released in 1987 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 Contra?
Eight stages of hand-built level design, which is most of what the game actually is. The pseudo-3D base corridors, effectively a second engine wearing the same clothes. Konami's name, the sprite art, and the cultural weight of a certain thirty-life cheat. 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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