I guess my biggest problem with the game is that if you hit anything and spin out, you might as well self-destruct and start over because it's impossible to regain control.
Flash games shouldn't have Premium Content. That's the first offense. The second one is that the sound, even when muted, likes to come back in really loud spikes at certain points, which is annoying. The gameplay is fun enough, but like many have said, other games are just like this and are done better.
I agree with what everybody is saying. It's a pretty stellar game with great tunage and solid, tried-and-true gameplay. I will admit a progress meter would have been nice and a volume control as well, but other then that...very good!
While a really good concept for a pick-and-play flash game, there are some crippling issues that need to be addressed:
Firstly, the controls. This is the biggest stumbling block. 'A' should be jump, no question. It's far more natural for the fingers to go after the far button to jump (a mechanic taught to us by Mario). 'S' is fine as bullet time, but having it toggle on/off instead and making a different key dash would make it so much easier to negotiate. Jumping with 'A', switching on bullet-time and then dashing around unencumbered would make clearing tougher levels even more satisfying.
Next, we need a instant-restart button. R is the obvious choice. It would just make going for record times easier in the long run.
Other then that, I think it's fun. The replays are great to watch and it's nice being able to feel badass in slow-mo. While it does have issues, it's a solid 7/10 all day. Good work.