For short, Looks beautiful and sound awesome, but the controls are confusing, it lacks visual feedback and the primitive AI prevents me to take this game seriously :/

Visual feedback problems :

1. Initial loading
   When I clicked "Dive in" for the first time, I waited for about 7 seconds before asking myself "wait... am I playing right now?"
   The sound were still playing and the found footage screen effect was still on, nothing but the knowledge that a message was incoming could tell me that the game was loading files.
   Potential solutions
   
   1. Just fading the screen to black would've made me wait a little longer
   2. Very simple "loading" text is sufficient to solve the problem entirely
   3. Fancier loading wheel to distract while waiting
   4. Get creative and make a loading animation themed on your game, some ideas : Oxygen bottle filling up, Shark teeth regrowing, Water ripples, etc.
2. Health visualisation
   While it's not bad to not show precisely how much health remains and I like the idea of more immersive experiences, I never know when I'm about to die. Since most computers can only communicate with the player via images and sound, you MUST tell them information so they know what is happening.
   For example on my first playthrough, after getting away with a dozen shark bites, I die after walking into a jellyfish.
   Also, game design pro tip : NEVER EVER put instant death traps (especially not in the starting zone XD) unless you alert the player that it'll kill him beforehand (I'm aware of the "beware of the environmental dangers" and that lionfishes are deadly venomous, but in games, ).
   Potential solutions
   
   1.  Add a screen effect (eg. pulsating red vignette or sepia tone) that increases as the health goes down. This also helps to let the player know how much a health kit can recover.
   2. Jellyfish and sea urchin stings could give damage but never kill the player, but also slow down the movement for a moment, so the player will still avoid them at all costs.
   3. Expand the "examine" function, in a Metroid Prime fashion, insert information about the species the player is looking at, tell how dangerous or deadly it is.
   4. If you can't find a solution to the lionfish instant death problem, just remove them.
3. Screen shake
   The screen shake happens when sharks appear, I get it, but for my first 3 attempts, I legit thought something hit by back, which is a shame because when sharks ACTUALLY chews my butt, nothing but a sound of muffled scream plays.

Confusing controls :

1. Why is it called "movement up" and "movement down"? Is it because I'm swimming? If so, then why do I always keep the same height from the ground?
2. Why do I have the binding to jump, crouch or prone but seemingly can't do any of those actions?
3. "Lean left" was by default binded to "Y". Little nitpick, but easily fixable.
4. Holding shift to run BARELY makes a difference (clearly can't change anything to the fact that sharks will pin you down anyway) but the vignette clearly shows that something is happening so Idk.

Primitive AI :

Look, at this project's scale, it's not a big deal if the monster of your game is an unfair unstoppable demon. But after the accumulation of problems listed above, it's pretty much the cherry on top that made me uninstall the game after about 6 attempts.
While I don't like the "monster" portrayal of sharks in essentially every movie, game or cartoon, I think you can get away with a devilish shark portrayal if it's otherwise faithful to the animal, which currently ((currently!)) isn't.
What I mean by faithful to the animal?

• Sharks are very sensitive on the nose area, this could be a weak point to exploit until you get a weapon.
• Sharks try to ambush its preys by attacking from behind and may play the uninterested if their prey looks at them. Would work better in more open areas, or if the corridors have a higher ceilings.
• Sharks hunt from below and therefore have a harder time seeking preys below them.
• Sharks are cannibals. (might require more complex AI) the player could take advantage of more sharks in one room if he's ready to take greater risks.

It's scary to know that a monster which outperforms my abilities in every way will hunt me down until I'm dead, but it's silly to see that monster push me against a wall and chomp his way through my non-existent health bar with the looping sound effect of muffled screams.

You really did put out a game with excellent visual quality and sound design, but it lacks the fundamental elements that build memorable experiences in video games.

I'm still interested to see how the game evolves and maybe some time later I'll give it a second try.

I'm wishing you the best!