Okay, I know this is your third game, and let me give you some input:
Bad: The music. Don't just use one track. It drones on your ears. The difficulty. You shouldn't have to pay to have challenge. Hard should be easy. The prices. The characters cost too much and should be lowered.
Good: For a 3D runner it's pretty average. And for your first 3D game it's actually fun.
Final Score: 3 and a half
-Seb