Crosswind
A longbow range at night. The arrow is a point mass under gravity and a vertical draft, integrated at a fixed step and drawn tipped by its own velocity, so the dotted hold-line is literally the same maths as the flight. Targets patrol on a swell, so every shot has to be led, and a fresh draft is rolled for each arrow — readable only from the windsock and the drifting motes.
* THE GAME RUNS IN A SANDBOXED FRAME — IT CAN’T SEE THIS SITE OR YOUR OTHER TABS. BEST SCORES STAY IN THIS BROWSER.
Cartridge promptTHE EXACT PROMPT THAT BUILT THIS GAME
Build a tiny browser game called "Crosswind".
Game spec
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A longbow range cartridge, playable with mouse or touch. Ballistics: one shared integrator steps the arrow under gravity plus a faint drag, and the aim preview, the live flight and the round generator all call it, so the dotted hold-line can never disagree with the shot. Wind is a vertical draft (a downdraft presses the arrow down, an updraft lifts it), rolled fresh for each arrow and capped to keep the course solvable; it is shown twice, once as a number on easy/medium and once as windsock plus drifting motes for players on hard. That axis is a measured decision: a downrange wind is absorbed by re-aiming, and a drag-toward-the-air wind eats the arrow's range until the far lanes cannot be reached at any angle. Three target lanes sit far enough out that the draft moves the winning aim by more than the whole winning window, so the flag must be read; the sight drifts constantly and a limited BREATH hold steadies it. Release to loose, score by ring proximity with a bullseye bonus, arrows are limited, clearing the range pays a bonus and moves to a fresh wind and swell. Tuning constants (launch speed, drag, draft strength, lane geometry) are chosen by measurement so that every lane is solvable in every wind the round can roll and no single launch angle works in all winds.
Hard constraints — the game will be embedded in a sandboxed iframe on a static gallery site, and a headless browser will screenshot it:
1. Output exactly ONE self-contained HTML file. All CSS and JS inline. Zero external requests: no CDNs, no external fonts, images, or sounds, no fetch/XHR/WebSocket. Any sound must be synthesized with WebAudio.
2. The iframe sandbox is "allow-scripts allow-pointer-lock" (plus an autoplay permission). So: no localStorage, cookies, or indexedDB (opaque origin — access throws); no popups, window.open, or navigation; no access to the parent page; alert()/prompt()/confirm() are silently blocked.
3. The playfield must be visible within 800 ms of load — that is when the screenshot is taken. No dead white screen. If there is a start screen, make it visually rich.
4. Controls: keyboard AND mouse must both work, plus on-screen touch buttons for phones. Call preventDefault() on game keys (arrows, space) so the page never scrolls.
5. The view is 16:9 and must scale to fill the viewport with no overflow or scrollbars.
6. Show a visible score. If the genre has a losing state, show a game-over screen with a restart (button and a key). Idle/clicker games skip game over but still need clear numeric feedback.
7. If you track a score, report it to the arcade shell so the player's best is remembered between visits: on every score change, call parent.postMessage({ source: "ai-arcade", type: "score", score: <number> }, "*"). It is safe to call it no matter what the parent does with it.
8. Keep it tiny: aim for under 400 lines, 60 fps, no frameworks. That 400-line target does not apply to 3D games — true 3D (a camera and perspective-projected world) or pseudo-3D (projected road/track, depth-sorted sprites) — which need their own software renderer and typically land at 800–1400 lines. The rest of this constraint still binds every game: 60 fps, no frameworks, no external assets, and no padding to reach a length.
9. Difficulty: the arcade shell passes the player's chosen difficulty as a URL query parameter. Read it with new URLSearchParams(location.search).get("difficulty") — the value is "easy", "medium", or "hard" (missing or unknown means "medium"). Make the three levels meaningfully different — speed, lives, enemy pressure, reaction time, whatever fits the genre; clicker/idle games with no losing state use starting resources and upgrade cost curves instead. Show the active level in the HUD. Without the parameter the game must be fully playable at its default (medium) tuning.
Return only the complete HTML file, no commentary.