The game is indeed challenging and, I confess, I didn't have enough strength of will to finish it. However I really liked the variety of physical mechanics, even though the concept of playing as a fish in a hostile environment is not new. I also like that at first the game seems like an old and pretty cheap web-site game that you don't even need to think about to get through, but this game puts you right in front of a tough challenge, so you really need some skill and patience to win.
Of course there were some bugs when I got clipped right into platforms, but overall the game is great!