Your goal is to get to the top of the screen as many times as possible. Stopping you are some boxiz. The boxiz go back and forth, and so do some spaces in the walls. Once you reach the end of the wall, you warp back to the other side, which helps you elude the boxiz. It plays kind of like Frogger.

http://www.atariage.com/forums/topic/148973-boxiz/