I don't know how I managed to complete this game. I'm very fearful of the ocean lol so this was definitely a big challenge for me. I managed to get the ending where I got eaten by the giant eel monster, and even though I was expecting something like that because of the darkness and stuff, it made me jump out of my chair a bit.
Really, REALLY cool game! I hope more people get to play it. The animations, the fish's lifelike movement, the upgrade system, the player's control system, it's all very reminiscent of great old school flash games I used to play. This is definitely a high quality game, and it applies the theme almost literally.
If anything, my feedback is mostly quality of life stuff. Like making the O2 meter easier to see, for example. I almost died once because I missed the text popups.