Dirt Bike
Free racing game · plays in your browser · made with GPT-6 Astra
Play Dirt Bike free in your browser: a racing game with nothing to download and no sign-up. It sits across physics and arcade as much as racing. It was written by GPT-6 Astra, and the prompt behind it is printed further down this page. It works on a phone as well as a desktop.
About Dirt Bike
Dirt Bike is a single-player 2D motocross game with twenty obstacle courses across a salt coast, red-rock canyons, night tracks, and high desert. Tackle 50 authored obstacle variants across ten families, including launch ramps, timed presses, pendulums, seesaws, collapsing bridges, breakable crates, powered rockers, conveyors, slick ground, and rolling drums. Courses remix these in changing sequences, with harder timing and skill jumps in later regions. Nearby checkpoints keep retries quick.
Independent sprung wheels and an articulated rider make throttle, braking, and weight transfer affect the bike. Land flips or balance on either wheel to earn trick coins. Finish to bank rewards and return to the winding campaign map. Stars unlock bike models, while coins buy them. Four bikes offer different power, air control, and suspension; every course is playable on the starter bike.
The compact top bar shows your level, time, pause, and sound. Big jumps smoothly zoom out, then ease closer on landing. Use Up/W for throttle, Down/S to brake and reverse, and Left/Right or A/D to shift weight. R restarts, Escape/P pauses, and M toggles sound. Large touch controls are included for phones and tablets; the ride camera interpolates physics frames for smoother motion. Stars, wallet, garage, and personal bests save locally. Sound starts muted.
How was Dirt Bike made?
The prompt behind Dirt Bike
Build an original side-view motocross time-trial game with a coherent illustrated desert identity, independent wheel suspension, responsive throttle and brakes, rider weight transfer, controllable aerial flips, checkpoint restarts, nine courses, touch controls, locally saved personal bests, and optional upbeat audio. Rename the game Dirt Bike and create matching square icon and wide preview artwork. Original development metrics, through first release on 2026-10-18: GPT-6 Astra with high reasoning effort; approximately 24 minutes; 6,350,773 cumulative tokens. Breakdown: 6,311,558 input tokens, including 6,023,424 cached input tokens; 39,215 output tokens, including 8,158 reasoning tokens. These totals include repeated cached context across model calls. HYPOTHETICAL COST, NOT AN ACTUAL BILL: $10.87 USD using Standard API rates of $10 per million uncached input, $1 per million cached input, and $50 per million output. Without caching the hypothetical cost would be $65.08. Source: https://developers.openai.com/api/docs/models/gpt-6-astra (checked 2026-10-18). Actual charges are unavailable. Later naming, artwork generation, and publication work, tool fees, regional charges, and subscription billing are excluded. The actual-cost field is intentionally unset. Version 2.0 campaign expansion: preserve the original handling while adding twenty longer courses, four connected map regions, checkpoint recovery, landed-trick and finish earnings, star-gated bike models, coin purchases, persistent equipment, and a return-to-map race flow. Keep old stars and unlocks while discarding incomparable short-course times. Validate all courses with ordinary control inputs, every checkpoint, upgrade handling, economy, persistence, and the standalone UI. Version 2.1 handling follow-up: holding brake transitions to reverse once the bike slows down. Sustained forward or backward rider weight transfer can unload one wheel, supporting front-wheel stands and wheelies through damped physical torque rather than snapping body angles. Front-wheel stands earn 20 coins. All twenty courses and bike-upgrade checks continue to pass. Version 2.2: remove riding HUD labels, control legends, center hints, and intrusive pause explanations. Keep a small pause button and essential touch controls. Freeze silently on lost focus, use a compact explicit pause strip, remove impact shake and speed-dependent camera zoom, and damp terrain-following camera movement. Replace repeated hill sections with wooden piers, trestle bridges, rollers, tabletop jumps, stepped mesas, quarries and ridges, with original region-specific landmarks. Preserve stars, coins, garage and unlocks while resetting incompatible course times. 27 automated physics, camera, save and UI execution checks pass; fresh visual browser QA was unavailable. Version 3.0: rebuild all twenty courses around six physical challenge types: spring launches over saw fields, breakable crate stacks, weight-responsive seesaws, timed crushers, collapsing plank bridges, and swinging hazards. Combine encounters and tighten timing in later regions. Restore only level number, timer, pause and sound in the riding HUD. Add smoothed big-jump zoom independent of ground speed and suspension bounce. Preserve garage, currency and stars while migrating incompatible best times. 35 automated checks pass, including every course on the starter bike and individual obstacle interactions. Browser visual QA remains unavailable. Incremental token counts and actual charges for this update are unavailable and are not reported. Version 3.1 fixes throttle-only completion: reproduced level six finishing on continuously held throttle in 67.88 seconds. Crushers now start their cycle on approach, with a visible sensor strip, brake sign and red/green signal. Checkpoint retries re-arm the cycle, so repeated automatic restarts cannot obtain a lucky opening. Spring kickers apply a physical front-wheel impulse that requires landing correction. Regression checks hold throttle through twelve retries on all twenty tracks and on every bike at multiple initial timings on level six. All twenty tracks remain completable with ordinary throttle, brake and lean controls. 38 automated checks pass. Saved stars, currency and bikes are preserved; incompatible best times reset for the revised obstacle rules. Browser visual QA and incremental token/billing data remain unavailable. Version 3.2 mobile and variety update: add at least 50 authored obstacle variants across ten families, remixed across the twenty courses. Add clear on-track art for conveyor surfaces, slick ground and rolling drums. Improve touch controls and smooth motion using fixed-step physics interpolation; retain the sparse level/time/pause/sound HUD and eased big-jump camera zoom. Preserve stars, currency and owned bikes while resetting incompatible best times. Incremental token use and actual billing for this update are unavailable; do not report them as known values.
Categories and tags
Questions about Dirt Bike
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- Is Dirt Bike free to play?
- Yes. Dirt Bike is free, runs in your browser, and needs no account. Nothing to download, no plugin, no sign-up — open the page and play.
- Do I need to download or install Dirt Bike?
- No. Dirt Bike runs entirely in the browser on desktop and on a phone. There is nothing to install and no launcher to sign in to.
- Which AI model made Dirt Bike?
- Dirt Bike was written by GPT-6 Astra, a model from OpenAI, using Codex desktop, Planck.js, Canvas 2D, Web Audio, built-in Image Generation. The prompt that produced it is published on this page, so you can see exactly what it was asked for.
- Can I play Dirt Bike on my phone?
- Yes. The creator says Dirt Bike works on a phone as well as a desktop, with touch controls.
- Does Dirt Bike have a leaderboard?
- No. Dirt Bike is not a game that ends in a number, so there is no high-score table for it — play it for its own sake.
Version 3.2.0 · updated 2026-10-21