My personal favorite of the three soundtracks of the Prime trilogy. While the types of voices and sounds used are very similar to the first Metroid Prime, this soundtrack is much darker and creepier. It is still electronic, but I bet you could find a few tracks suitable for a fantasy or horror game not in the future. I still wouldn’t ever use the battle tracks (everything starting with “vs.”) in my game though, it still sounds too video gamey for my taste.
The general atmosphere of dark ambience is great, especially for the “dark world” themes (those starting in “dark” such as “dark torvus bog”). There is in my opinion 25 solid tracks on here: landing site, hive tunnel, the ing, elevator room, exterior, temple grounds, luminoth energy controller, a-mos’s account, light temple, agon wastes, item room, space pirates lurking, pirate fear, dark samus appears, puzzle theme, dark agon wastes, torvus bog entrance, torvus bog, dark torvus bog, submerged temple, dark submerged temple, dark energy controller, dark sanctuary fortress, dynamo core, and sky temple.