I'm sorry but...
...while the graphics are nice, the animation is really smooth and the music isn't bad, there are a lot of problems with this game.
The first issue is that the controls are REALLY frustrating. It's not a hard game, it's just the controls are simply ridiculous. That brings me to the second issue, that if the controls were balanced, the game would be incredibly dull and repetitive. There's no real obstacles or hazards, no consequence for flying off the track, no computer opponents to race against and no real goal other than beating friend's highscores (if you have facebook) which there's no point to given the previous problems.
It has the potential to be a really fun game, but right now it's little more than a racing engine with bad controls. You should try to rework it with better gameplay and then resubmit it. Good luck.