A race car obstacle course that's fiendishly difficult and fairly addicting (and on occasion rather unfair), and the road is randomly generated so it's never twice the same.
Visually it reminds me of Tron, and the soundtrack is very reminiscent of old mod tracker music.
The game announces up-front that it's difficult in the splash screen. It's not wrong.
Two tips: play fullscreen, and turn slightly later than you think you have to.