I absolutely love the music, what's the source? Did you write it yourself?
Graphically this is also pretty amazing. I love the particle effects, and also the little design touches: the radial lines as guides, the flashing/audio cues when seeking - design-wise everything just hangs together really really well. One of my favourites of this jam.
About the only thing I could find to criticise it would be a slight floaty feeling to the controls - to my mind, just a touch less inertia would have made things feel really tight and responsive. But that's a very minor point in an otherwise excellent entry.