Press the green flag. If the string/the white line is touching the shark then just press the up key a bunch and after it should work fine. Right and left keys move the boat and up and down move the string. You are trying to touch the fish and the octopus is worth either 15 or 20 points. Try to get higher then the high score which is 110. If the string touches the shark then it is game over! Have Fun!
Came up with the idea all by myself.