Thanks for the in depth comment.
I'm not much of a sound designer; I'm still learning, but as long as the sounds creep out the player, its a win for me!
Some other people had trouble with the tutorial text disappearing too quickly, which is entirely on me, I could've very well fixed it in the time I had remaining, but thought it was fine for whatever reason. (Don't worry, I have a better fix planned for it).
That's actually a good idea to add obstacles, like maybe exploring caves or navigating around underwater mines.
I would argue the zoom feature is actually more useless than the flashlight, but I mainly added those features for more of a "realism" reason than a gameplay reason. I suppose I could incorporate those features better with the gameplay by having tasks require you to use them in the future.
The only real reason why I didn't add full resurfacing is that (and this was my number 1 reason) I didn't have any fish or any other sea life, and ascending upwards would make it feel unrealistic as there wouldn't be any sea life visible (kinda a weird reason looking back on it, but I also feel like the lack of sea life adds to the creepiness). The other reason is that it would take too long, especially in the later levels (which is a better reason than that previous one, but I do think the exploration gamemode will require you resurfacing all the way and descending all the way down).
I was waiting for someone to relate my game to Iron Lung. I tried not to make it too similar to that game, as I of course want this to be it's own creation, but there are some similarities (who knows, maybe I could add the Iron Lung monster into this game in the future ;)
Sorry if I waffled on for too long, I sometimes write these long comments as notes for myself on what to add for the full release, but any other suggestions are welcome.