I really like the art, music and gameplay, but there could be a lot more in this game that would make it perfect.
First, I hope you can give higher time bonuses for the things you pick up and the tricks you make. For two backwards flips, you get 0.02 seconds of time extra! That's nothing compared to the final time. I can better slow down a bit before a jump so I can continue to ride quicker than to make 5 tricks in a jump to get 0.05 seconds time extra.
Secondly, a level editor would be really great. 20 levels that can be cleared in less than 6 minutes isn't much. If you include a level editor, a lot of people can get really addicted to this game, and play it for more than six minutes.
Thirdly, I'd like to have my total time on the screen when I complete all 20 levels. You can also include ''staff times'' to see where I can get a few seconds off my time and where I've done really well. Because now I don't know if I did well or not. I hope you can change these things.