I love little games like this -- with a single, unique mechanic. Catch-22 is a game that burst forth from Game Jam in Amsterdam, and now the team is hard at work preparing a complete version for release on iOS and Facebook. It's pretty difficult to explain, so I suggest you just watch the video!
Alright -- I'll have a go at describing it. Catch-22 is a game in which you alternate between controlling two spheres in orbit, spheres that are travelling in opposite directions from one another. When you are controlling one, the other sphere continues along the path you created when you were last in control of it! The point of the game is to try and make it so the spheres never come in contact with on another.
See! Confusing, right! Man, just watch the video! I'm terrible at explaining things!