We’re familiar with free to play games, but how about a game where you pay what you want (PWYW?).  Proun is an abstract racing game available today for download and you can pay any amount you want for it, including nothing!  Folks who pay the minimum donation of $2 get a bonus track, but you can truly play the full game on the cheap.  Proun has you controlling a ball as it races along the outside of a pipe as you dodge all sorts of artsy shapes.  The game features 4-player splitscreen, racing against your ghosts, online highscores and modding, so extra user-created tracks will become available.  Proun looks like a fun, but challenging racer that has the potential to make you ill from motion sickness, but remember it can be free if you want it to be. [via GamePro]