I am the biggest soundtrack fan I have ever met. I have a huge collection (a physical one), I write soundtracks myself and have had moderate success with that.
Music in a game is probably even more important than the actual gameplay for me. I'm not talking about whether it sounds nice or 'epic' or whatever, I'm talking about 'does it add an extra layer to what I am experiencing?'.
Hang on I'll copy paste something I wrote a while back.
There's a lot of different ways to rate a soundtrack. If it's fitting, great, then it's at least adequate. If it's not fitting, but sounds good on its own, then it's at least fine musically. If it fits but is boring as a stand alone listen, then it's boring. Etc etc you get the idea. But a truly great soundtrack isn't just fitting and fun to listen to. It's more than the movie/game. A truly great soundtrack transcends the game. It becomes so much more than background filler noise. A truly great soundtrack makes the entire thing work. A truly great soundtrack can create an entirely different emotional feel.
Take the American Beauty soundtrack. Without it, the movie is cliché, artsy bullshit. The paper bag scene would be pointless, and all the peace and quiet in the movie would be draggy. With the music, everything becomes actual art. The long scenes are magical and the bag scene is the most beautiful thing you've ever seen.
Better example, Halo. Don't start bitching, stay with me.
Halo is nothing but a generic shooter. Faceless human soldier VS hordes of evil aliens on a strange planet. This game has nothing going for it in the ways of creativity or story or whatever. However, and most people experienced this subconsciously, the incredibly modest and calm soundtrack turns the game from a generic fragfest into something much more substantial. The monk choir turns the main menu into something beautiful, and puts the player's mind at ease. But, more importantly, the music is always sad. Even the most epic of battle songs always have this hint of loss and sadness to them. This gives the player the feeling that even though he's kicking ass, it's all going to be for nothing. The war is almost lost, humanity is screwed. All throughout the game the MUSIC is reminding you that there's a true sense of urgency towards what you're doing. You truly are mankind's last hope.
Or in Battlefield 3, in its super-hated single player it had one of the best soundtrack moments I've ever experienced.
In one mission, you're part of a three man squad chasing down a guy carrying a portable nuke through Paris. It's the most hectic mission in the game. You are constantly running, running, shooting and running some more. It's super hectic, cause if you don't stop the nuke, Paris will explode. At one point, one of your buddies dies in an explosion. Naturally, you turn and stop for a moment, but since you have a job to do, you have to turn around again and you have to keep running even faster. Now, instead of some crappy upbeat Hans Zimmer thing, the game does something amazing. It mutes all other sounds. You don't hear anything any more. No gunshots, no shouting, just this:
And you just keep running.
You didn't even know the guy who died. This was the first mission you had with him, so you didn't get time to care about his character. But through the music and sound design alone, the game pulls you in towards an atmosphere that is almost surreal. You are stunned. You cannot believe what just happened. This one, tiny minimalist piece of music has a quintillion times more of an impact than any cliché as hell sad angel-choir or violin ensemble could ever dream of.
And that, ladies and gentlemen, is how you soundtrack.
A good soundtrack doesn't sound like it was written for the movie/game.
A truly good soundtrack sounds like the movie/game was written around the music.
