Very nice! Quite polished and developed for a jam. Clean UI and overall visuals. I was a little confused initially, because the submarine is facing the opposite direction from which the keys are bound to. I pressed the down key thinking my submarine would move in the downward direction so I was really disoriented when my up key my sub go down and my down key made my sub go up. It wasn't a huge deal, and I was able to figure it out eventually, but it made for a really confusing start to the game. You could either switch the up/down keys or flip the sprite at the beginning (which I know may not be ideal since the sub is submerging haha). This is also just a nit-picky thing but I would suggest making the dock station interactable with keys. Since the player is only using keyboard buttons to play the game, it feels unnatural to take your hands off the keyboard and move it to the mouse, especially in this situation in which both hands will be on the keyboard.
Awesome job! Very clean :)