This is a song I wrote some time ago for one of my ex girlfriends, the original has lyrics, but I thought the instrumental version could work quite well in a video game.  It starts out very slowly, maybe while the player is learning the controls,  then it gets a little more complex and before you know it you're flying through it with things going off everywhere :)

 I'm posting this under GPL 3 and asking to be attributed. 

As always, if you use this, I'd love to hear about it!