Nice game
quit after I got dizzy :P
I didn't like how the bigger fish couldn't eat the smaller fish but, then again balancing the game would be really hard if you had to basically put natural selection in a game.
I didn't like how I kept running start into the jaws of the bigger fish but that was basically the only thing that killed me so you might wanna keep it that way. I also don't get why the bigger fish aren't faster than u... might be for balancing but maybe you could make the turning angles bigger for the bigger fish, but you could also add some speed to them. (smaller fish have sharper turns)
Good luck