I haven't finished the full game because I want to test as many entries as possible and there is quite a lot to test :)
The farthest I made it so far was a bit after the spiral painting.
The under water ambience sound is great and really fits well. I think it was mostly the hissing sound of the navigation that put me out of it from time to time. Turning the volume of that a bit more down could help feeling more drowned into the void. I also thought if it would be good to attach a loudness curve to the proximity alert so the closer you are to a wall the louder it gets.