I agree with elitestratman, this is perfect bgm. Minimalism is a powerful tool when scoring anything. It might not strike the listener on the first listen by itself, but this kind of stuff tends to work its way into your brain and then you find yourself loving it and throwing it on to listen frequently.
Also, the track really opens up later in a huge way and totally takes a directional shift away from minimalism. There's probably a handful of tracks in this 15 minutes that could be separated out in different layers and used in a whole variety of ways within a game. This could almost be a showcase of many different moments that are scored in the game.
Great work!