Puzzle / Rhythm Action hybrid
It's difficult to describe the gameplay in this. Various things float around the screen in a similar manner to Asteroids (best example I can think of). Your task is to move your little ship around the screen and tactically self-destruct in order to create chains of explosions of the other things in close proximity. The more the better, all in time to the music (it's from the Rez/Lumines guy).
I'm currently thoroughly enjoying it. Great portable title.