With the mediocre reviews for this game, I've only recently finished it, now playing it again through the higher Mayhem difficulties (and having a blast).
But the OST... you only get a glimpse of this in game as it cuts the music off too fast. Have you guys heard it? Jesus Christ, this thing is amazing.
Just listen through some of these songs, there's 6 or so hours here.
It's like a mix of old mech warrior (90's) ambient stuff, synth wave and god knows what else.
It's amazing stuff.