Keep your finger on the display and move it around to collect as much starfishes as you can. The faster you can collect them, the greater your bonus score will be. While this sounds easy, there are also fishes that you must dodge. As the game advances, more fishes will appear.
There is a offline as well as an online highscore list which allow you to mess with other players from all over the world.
If you like this game, buy me a beer :)