It's a very nice game, the artstyle has so much personality! But I have a few critiques, mainly the fact that the hitboxes of enemies are very large, and you tend to die a lot because of it. Also, it could use a visual or audio warning for when you are about to run out of oxygen or pressure is too high, as I didn't notice how low I could go at the beginning. Also, hazards aren't very clear: there are some smaller fishes that can kill you, although others you can just grab with the net, also ambient hazards through the map aren't as obvious. The voiceover could be nice, but I quickly got tired of hearing it over and over when dying, but I could see it implemented better and less repetitively in the game, as it actually adds to the overall personality of it!
Also I couldn't figure out how upgrades work (but maybe I'm just stoopid lol), but for the rest the game explains the controls flawlessly.
Overall great game, could use some polish, but very full of personality and that's a thing I love! :D