Upstaged!
I don't know how long you've been working on this, and I'm not going to say you didn't work hard...But if you're going to make a dolphin shooting game, you need to take a few pointers from Torpedo Joe, a very funny flash game in which you torpedo dolphins, manatees, and merpeople...The sound effects are positively annoying and repetitive, but the game is worth it just for the rare moments you get to shoot one of the merfolk. My point is, it needs to be smoother at the very least. The rigid dolphins with their painted targets makes it look too much like a carnival game...Obviously you weren't going for any gross out factor, or they would have been a lot more life like, with more gore. Don't be discouraged though. You'll get it right if you keep trying.