Drawing. Q pencil, W straight line, E eraser, R hand, T start flag. 1 2 3 pick a normal (blue), acceleration (red) or scenery (green) line. Lines are solid on one side only: drawn left to right the top is solid, drawn right to left it is a ceiling. Hold Shift while you start a line to flip it. Acceleration lines push the rider in the direction you drew them. Line ends snap to nearby ends (S toggles).

Moving around. Scroll or pinch to zoom around the pointer, drag with the middle mouse button or two fingers to pan, H jumps back to the flag. Ctrl+Z undo, Ctrl+Y redo.

Riding. Space plays and pauses, X stops and resets, M toggles slow motion, F fullscreen. Land too hard, hit your head or come down nose first and Bosh parts ways with his sled. The ride is fully deterministic, so the same track always gives the same run, and you can scrub the timeline or keep editing while paused.

Saving. Tracks save in this browser only. Export gives you a JSON file, Share link packs the whole track into the address (small and medium tracks; very big ones need Export).