First off, I like the idea of the game, and I think if you iterate on the art, making it more dark and gritty, it could be a cool, claustrophobic experience. The controls, or rather the collision, and especially the orientation of the playermodel was rather strange/buggy. Often I was crawling left or right, but the model was orientated as if I was going down.
Even though I just admired the claustophobic experience, I still think the view should be zoomed out a little bit more, giving you a bit of space for at least an oxygen meter. Felt rather dull to die all of a sudden, having no info on my oxygen beforehands. And maybe a minimap, revealing the paths you have already explored. The animation was simple, but fitting for the artstyle, so no negativity on that. I think the sound was pretty good.
I have to add, since the menu was cut off for me, I might have had problems with resolution/aspect ratio.
Overall a good entry to the jam