Nice, simple gameplay! The controls are very responsive. I like the look of the player character though I have no idea what it is. The achievements were a nice addition.
Criticisms/Suggestions:
There could be more going on visually, some details on the walls and something in the background, and visual effects when you go through a hole or crash into a wall.
Music could be longer. Also, it doesn't loop seamlessly. Sound effects would me a welcome addition.