I think this is one of the more impressive diving game concepts that this theme has had. I do feel it's way too difficult for a GameJam game. I couldn't find any treasure / collectibles and I also couldn't tell where I was being bitten from. The octopi took all my focus to try and get them and eventually I just drowned.
BUG REPORT: Your "Restart" button doesn't work.
I do feel this has the promise of something good but I think it needs some rebalancing perhaps?
Good job on finishing this in one week!