Wow this is incredible, it's pretty much ready to put in a game. The atmosphere and instrumentation is very strong and it nails perfectly with your setting. It is also quite varied for such a large ost. My favorite aspect tho is that with the lack of structure the music feels very organic, I feel like if you put it in the game the track could be interactive with the environment or the player actions. Also this feeling helps since the tracks are also connected to the next one, which sounds great. Amazing work!