Motocross
A 2D physics dirt-bike — with a built-in level editor.
- Controls
- Status
- Difficulty
- Session
- Stack
- Vanilla JS + Canvas 2D
- Generations
- 1
- Bundle
- games/motocross/index.html
About the machine
A 2D physics dirt-bike game with a built-in level editor. Reach the checkered finish from the start without the rider hitting the dirt; best time is kept per track. The editor builds terrain as a smooth spline through control points, places start/finish flags, and saves, exports and imports tracks as JSON — three demo tracks ship built in (Rolling Hills, Whoops, Big Air).
Generations
Generations
PromptPromptmotocross single player with level editor
What changed
The original zero-shot build. A custom rigid-body simulation: a chassis with two wheels doing spin-based traction (friction opposes the slip between tyre surface speed and ground), wheelies from a rider weight-shift model, free rigid-body air rotation under lean torque, suspension that absorbs landings, and crash rules. Heightfield terrain sub-stepped at 1/240s so fast wheels cannot tunnel on steep faces.
The Audio department synthesized a continuous throttle-tracking engine plus landing/crash/finish sounds procedurally via Web Audio. QA'd against headless physics tests (settles at rest, accelerates and rolls, pops wheelies, flips in the air, all demo tracks completable) plus editor round-trip checks.