It has a dubstep soundtrack that is pretty good, considering my opinions on the genre. You have limited energy to shoot with, and you get more energy by letting enemy bullets hit this force field thingy that pulses around your ship. You can also slow time with the energy, which slows bullets AND the music, which I thought was neat. I think the ships and bullets might act depending to the music, but I'm not sure.
Also, the majority of the music is from people on newgrounds. Nice for them to feature it in the game to get them more err... publicity? There's another word I was trying for but I forgot it.

Here it is: http://www.newgrounds.com/portal/view/584352