A few people asked about the music used in the Voxatron preview trailer, so here's a copy in mp3 format & the original .xm. Note that I wrote it with the trailer in mind, so it's quite short! For the final soundtrack I'd like to make an extended version.
The tune was written in Milky Tracker, which you can also use to view/play the .xm file. There's a bunch of unused pattern data lying around in there, which I sometimes like to have a nosey through in other people's tunes to get an idea of how it evolved.
Most of the instruments are generated by the in-game synthesizer and derived from game world sounds: the drums are from collisions and the sound of bullets hitting the armadillo shell, etc. If you'd like to use them for anything, feel free to grab a copy from the .xm.
I initially had all the music planned out and was keen to write it myself, but it might also be great to have a bunch of guest artists on the soundtrack. Let me see how the game develops and I'll get back to you on that.
Awesome stuff man.  Are you planning on attending the Game Developers Conference in a few months?  I'd love to try this out.  Also is it just desktop comp gaming right now or are you thinking possibly porting this to android/iOS devices?   (found out about your game via ArsTechnica).