Geometry Wars: Retro Evolved: $5
The main goal of this game is to blow up the geometric figures without touching them and dying. As stupid as it sounds, Geometry Wars is one of the most intense and fun games I have ever played. The graphics are simply beautiful. Unfortunately, this game requires a Xbox 360 with a live online subscription. But if you don’t want to shell out half a grand to play a $5.00 game, you can just download Grid Wars 2, a free clone.