What you'll get here are 24 tracks of ambient, post-apocalyptic bliss. You could probably toss words like "ethereal" and "haunting" into the mix too if you felt like it. Really, it's an amazing collection of some truly epic tracks. We're hard pressed to name a better ambient score to any major motion picture, let alone a game.
So in summation we have a free remastered and remixed collection of an ethereal and haunting soundtrack to one of histories best computer games series. If that didn't work as a selling point than you've got something mixed up in your head.