The issue with the song Pillar of Awesome (
http://www.newgrounds.com/audio/listen/425329)
is that while it's pretty rocking, it'd get old fast as a menu song. Also the whole being sampled from legitimate songs being potentially legally troublesome thing exists, but mostly just the 'getting old' part is enough.
Either way, EnZero has 2 other Halo songs on his newgrounds account, maybe that'd ease your pain while waiting.
http://www.newgrounds.com/audio/listen/445736
http://www.newgrounds.com/audio/listen/443098
Also from a UI perspective the menu is kinda gross.
Why would you have Profile seperated from Customize? Even then, why are both main menu options? Customize should be a sub choice after selecting profile.
Leaderboards? For what? Friendlist too - again, why are they on the main menu?
The backing section and menu options are huge, approaching the title font size.
The title should be a touch smaller, and the menu options much smaller, and the transparent backing much less imposing to show off the background.
oh well, bit late now, eh?