Thanks for all the great replies.
I would allow you, to use my existing tracks, but I have developed a lot in the last 2 months, so some stuff could be not as good as I would do now. I also don't know what you need for your game, if it's only supposed to be background music my current album would be working, but for some situation based music I had to compose some new tracks.
I personally would prefer to compose some new music. If there is no challenge for me and you are already comfortable with my current album, there wouldn't be something for me I could work on.
I also got some programming experience for about 5-6 years now and if you tell me, how you implemented looping songs and how your sound engine works, I could easily do some songs that fit your needs