Remember the demo of Project X with the speed section?.. Well how about a small game that expands that idea into a small self contained game, you could have a music module that is matched to the length of the level, the music it's self could start off quite calm but progressively gets more intense as you progress to the end? I would be more than happy to provide the music if required
Possible power-ups such as score multipliers, slow time and temporary invicibilty. A high score saver?