Wow, incredible execution on the concept! I'm not sure if there was an end to this one, so I just got as far as I could (about 5 rooms) before exiting.
I think the fishing hook takes a little too long to use, but that could be a "me" problem. It doesn't feel entirely responsive, but given the time constraints, it's fantastic. The use of bullet-time when you're aiming is also incredibly helpful. Works very smooth. The gameplay loop is a bit tricky but after a minute everything clicks and the mechanics just feel great.
I especially like that feeling of panic you get when you're stuck in the water. You can't use your rod so you have to just quickly jump out. Adds to the tension.
Fantastic job!