There is a vertical 2-sided window with blocks between players with fishes and other sea creatures on the blocks.
Bottom of the window is 2 rotary dials where 2 pictures appear every round.
Both players run at the same time the rotary dial. If it stops, players must find four pictures which are on the two rotary dials. If they find, they must push these blocks through the game window,

Player with the least blocks is the winner if there are no blocks left inside the window.