Quite fun!
I guess the main reason I enjoyed this was because there were a lot of medals. I also appreciated how the music was so nice. I wasn't sure that touching the other fish was going to cause you to die, but it was pretty evident it would. Another cool thing was how you were able to electricute the other fish. You have to get better, because with every bubble you get another dang fish pops up. My only complaint is that the fish here don't seem to be well designed.
Some of them look ugly. Then again, seeing as how they're fish that can hurt you, I guess it makes sense. The sound effects are good, especially the nice bubbling noises. I like how you have a lot of room to go out and explore (before the other fish come up, obviously). It's a fairly simple game, but a pleasurable one.