It took me a while to realize that M2 is the right mouse button. The controls are very slippery. Both the acceleration and normal speed are really high so I kept bumping into spikes.
The music is cool but it would be better if it didn't loop all the time (maybe that's just time constraints; who knows).
The connection with the theme is very loose and it mostly adds to the atmosphere (though it is quite cool; the game has it's own visual identity). I liked that fact that you can choose your color. It's a small thing but it was quite nice.