Goblin Base: https://www.youtube.com/watch?v=_hY13AQNuCw

Crypt: https://www.youtube.com/watch?v=vXwZqEdyx40

Arx kingdom/underground lakes: https://www.youtube.com/watch?v=KscrvuH8YRs

The Order of Edurnuem: https://www.youtube.com/watch?v=iR_cWEad_FM

The Noden: https://www.youtube.com/watch?v=JU6xscAgQaA

Sacred Dagger: https://www.youtube.com/watch?v=4yWoTNN8HUY

Ylside assault: https://www.youtube.com/watch?v=JTgfWc_UbQA

Temple of Akbaa: https://www.youtube.com/watch?v=OAw1q6Llzsc

Credits: https://www.youtube.com/watch?v=jYDe0H3AXok

Less memorable/purely environmental effects:

Ice Caves: https://www.youtube.com/watch?v=x0kmYRUuZd4&list=PL9IMw3_4BTwzToG_DqpzCiRB_VkcKXsXk

Caves: https://www.youtube.com/watch?v=50crUklYFkg

Tavern: https://www.youtube.com/watch?v=mrIvX5SpcIw

Such a mystifying cumulative masterpiece. Arx is one of few games where nothing but ambience would be suitable, is one of few games where ambience is done so well, and is one of few games with a wholly ambient soundtrack where I can listen to the music and be immersed in the game to some degree without even playing the game, at least that's the best I can describe my emotions when I hear the music. It's almost as If I am in the simulated fantasy land of Arx again.

Anyway, this is all (I think) the tracks compiled in one thread, if it's not useful for you it'll be useful for me.

Credit goes to Arkane Studios/Floodgate Entertainment (developers) and TheTwinAce (uploader).