Pretty fun, I played it for about 10-15 minutes. I thought the main mechanic works pretty well, and I found it interesting how one of the main challenges is to get BACK INTO the water ASAP before your breath runs out. I never died from the bears, just from getting stuck or running out of breath.
I thought it might be a slight improvement to have a visual indication of which parts of the water you are able to swim through. I kind of figured out that there's an invisible wall somewhere underneath the bears that you have to jump over, but maybe some kind of bubble animation or seaweed or something to help indicate how soon you can go back down into the water and still be able to swim forward. Unless you intended that to be part of the challenge.
While the graphics weren't what I would call "pretty," I appreciated that they are functional enough to do the job, and thus the game has a bit of a bad art charm to it ; )