The biggest issue with this game is the camera. Subtle mouse movements adjust the camera drastically which makes it hard to control the character. If you reach a checkpoint and fall off of a high platform, you also have to kill yourself to respawn at the top which is kind of annoying. Maybe add code so that if you fall below the checkpoint location it automatically respawns you at the checkpoint.
Fun graphics and music though, and I think the concept could be really fun with a few improvements!