It's been done
Sorry dude, but the whole "Act like a shark" has been done before and better. I hate to say it, but the "Miami Shark" series did it a lot better. My main beef with this was that the controls were so, well, hard to control. It just seemed like I was swimming all over the place with this. The thing about this that was good was the music. I felt like it really gave me the feeling of being in a deep sea are hunting for fish.
The graphics aren't terrible, but they need improvement. It didn't even seem like the rival shark was much of a threat to you. Granted, that's probably good, because this game isn't the easiest to get high in the ranks. I think you died when you got out of the screen. I am sorry, it was just hard to control and have fun with you.