Move the mouse to steer, hold the button (or space) to jump, and press P to switch the screen between clean, eight levels a channel with dither (a Mega Drive) and the NES palette.
Everything is one useHelperLines buffer rewritten each frame. The camera never moves forward: the world comes to it and is recycled at the far end, so the numbers never grow.
The jump is mostly the field of view widening, and the three looks are the engine's own post chain (dither and paletteMatch).