So in terms of amount of time wasted to a game Warframe is in my top 3. No matter how many times I listen the Second Dream score just has so much emotion behind it, it makes the song sound so damn pretty. Also even though there is clear voice, no lyrics are stated so I think it still falls under soundtrack. Let me know what you guys think! Even though it repeats quite a bit I still love the melody so much I just stopped caring. A lot of the other scores from this game are fast paced and drum oriented so if you like the sound of someone going absolutely ballistic to a set of drums you're in for a treat.