Very impressive for a two day jam. Like an underwater horror game..!! Nothing is much more frightening than tilting the cam up and realizing you're right under the tail of one of those monstrous anglerfish... xD   (although I didn't let the monster catch up with me.... so I could change my mind on that one....)

Really nice visuals, great atmosphere. Loved your take on 'HP is power' - health of the player literally being linked to the submarine's power supply, making you balance the need to move your sub as far as possible with the energy you'll need to retrieve the gears later. Really amazing work!

Some constructive feedback for you, which I hope will help if you choose to expand this into a larger game! (Note, this isn't criticism in any way - the game is awesome, especially for such a short time, I just wanted to offer some pretty minor thoughts. Feel free to use or ignore any of them!!): 

• I loved the idea of the sub's power being linked to the power you have outside while swimming, but I think it could be made clearer to the player that this is happening, since I had to work it out, knowing the theme of the jam.
• At first I found gears a little difficult to find in the bleakness of the water, so you could add some sort of subtle indicator to them, like a very slight glow or something. (Honestly, this was only an issue for my first playthrough, after which I saw the gears float down after I got out of the sub, and quickly realized there are actually quite a generous amount on the ground for players that swim in different directions. So maybe this isn't necessary, but I thought I'd mention the idea!)
• In the panic of returning to the sub, I sometimes found the entrance difficult to get into, which resulted in my death at least once. The entrance could be more obvious, or you could be more lenient with where the player needs to be to enter the sub (e.g. if they're somewhere near the back, or even if they've just reached any point of the sub, they can enter). Sometimes it can be difficult locating the sub in the first place, so it's a shame to find it, swim through monsters, get to the sub with the last of your power, then die because you can't find the entrance! xD   (but maybe that's part of the thrill, I don't know!)
• I found getting the gears into the box in the sub difficult, and this took me several attempts for each gear. Maybe just allow a click near the box automatically place the gear inside, rather than relying on the physics system.
• Some kind of visual feedback that I successfully increased the sub's power would be cool, too. Like a blue flash lighting up the whole inside the sub or something, and/or the dial lighting up so it can be seen from the back of the sub.

Nice! i can't even understand how you can make something like this in a short time. The atmosphere is really nice. As a side note i think little bits of challenges would be nicer like repairing the submarine without being seen or stopping the submarine when something that detects sounds get close, things like that. Game is really nice at first and i feel bad for writing this but it gets a bit boring when you get used to finding the gears. Nice game overall though keep it up :) 

very original game, good.
Can you check my game too? :D