Aeterius is a game for the iPhone and iPod Touch that has you controlling a spaceship in an intergalactic game of bumper cars.
In this game, you control your ship by using the accelerometer. Your ship doesn't have any guns on it, but it sure does have two bumpers on the front that you can use to bash your enemies out of the way. To clear a level, you need to push all the other ships into an object or off the screen, causing them to explode. This sounds easy, but considering the controls rely on the accelerometer alone, you're going to have to spend a good deal of time learning how to control your ship.