If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Ride the half-pipe and gain height as you perform stunts before you land. Get higher for more stunts
Use Z, X, C, V, B, Up arrow, Left Arrow, Right Arrow keys to do some tricky stunts.
Down arrow key to land on the half pipe.
Space bar to increase power.
See inside of the game for further instructions.