I like it!
There has been few games so far that utilize sound well, I think you're in that grouping! I also like that oxygen just refreshes instead of accumulates. It stops snow balling a bunch of oxygen early but rather it creates literally 5 seconds of tension EVERY 5 seconds.
I like the map as well. Laid out well, hard to navigate on first play throughs, but after a few deaths I started moving FAST through it.