ImpossibleRubix Atmospheric is one way to describe it. The variety and depth throughout is noteworthy. While it retains a very dark ambient sound throughout, there are many peaks of light through the darkness that we can see which add a texture to the overall experience that makes it unique. Try pairing it with a similarly toned activity; it adds another level of immersion. I listened to this while playing EVE Online and boy did it make things interesting. Alone, the album can be slow at times.
Favorite track: Act 3 - Where it all Began.