Awesome that you did everything by yourself in this short amount of time. I read that you wanted to keep instructions to a minimum and I think it worked out really well, because as a player you tried several things to figure out how to survive. It would have been great if there'd be a bit more feedback, especially with the fish at night (was it possible to eat it? My player always said he was hungry) and the enemies.
Also the water shader was really cool!