Great concept.
Complaints:
*The camera is really annoying. When I jump normally, the camera should not move.
*When I climb stairs, the arrow keys also move the page up and down. This wouldn't be a problem if it was a standalone executable, but is when its embedded in a webpage. Should've had a way to change the default controls.
*The game could be longer.
*There could be better backgrounds
*There could be more music