I just love FREE games for my iPad. The NinJump HD is another great freebie (however, don't know how long it will be free). This game is action packed and it is not as easy as it looks. You are a super jumping ninja jumping from side to side while climbing up between two buildings. You must avoid flying stars, birds, enemies and obstacles. There are plenty of power-ups and and surprises to boost your score.
Fun game and did I mention it's FREE!!!! I don't think it will be free for long since it is a really nice HD quality game.