iStunt is an addictive 2D Snowboard action-packed game with a strong emphasis on physics. Traverse 60 different, surreal levels in an attempt to either score as many points as possible by pulling off amazing stunts (Stunt Mode) or getting to the finish line as quick as possible (Time Trial Mode). Achievements are included with OpenFeint!
Making things even more interesting is the occasional gravity inversion field which requires physically rotating the device 180-degrees to get back on track. (Text adapted from toucharcade review)