That is a interessting concept!
Loved the voice acting! Loved that the small rocks would bounce up, that added some extra difficulty. However the mouse spinning is a bit problematic on my multi monitor setup quite often the mouse movement was not registered because the pointer was on another screen, I guess you need to add some mouse capture. At some point I got invincible as the collision stopped working so I could play to end with no effort. I also liked the idea that the damage scaled over collision time.
To bad the final boss was not implemented but I thats fair, I could not finish mine too.
Good job!