You are a square, a 20x20px square to be exact. Jump your way through the levels without hitting anything. "One Square at a Time" is an open-source arcade game and is similar to the flash game "Space is Key" by Chris Jeff. It is programmed in Python2.7 using pygame, therefore it should be easy to port to lots of other operating systems, but I can't test that at the moment, since I'm doing the work on my desktop Linux PC.
Minor update: * Modified controls: - You know jump py tapping anywhere on the screen.