The game requires players to line up blocks in rows of 3 or more in order to allow your diver to delve deeper into the ocean. This occurs as you move blocks of various sizes (1 x 2, 2 x 1, or 2 x 2) horizontally into a column of coloured blocks. As you move blocks in from one side, you push blocks out of the other side. You can move these blocks up and down the column, as well as rotating their colours configuration, in order to create matches of coloured blocks within the column.
As the diver progresses he'll slowly begin to lose his air supply. The player has to refill the diver's air-supply by clearing rows of blocks quicker or finding and clearing a row of 3 special blocks that will appear randomly as the game progresses. Darkness falls from the top of the screen as time goes on too, which makes it harder to make matches.
There are two modes to select from in the game, Timed Dive and Free Dive. Timed Dive requires you to clear blocks until the diver reaches a certain depth before he runs out of air, at that point the level will end and the diver descends to the next stage. Free Dive is a never-ending puzzle that tests how deep your diver can go before he runs out of air.
There is a relaxing Aquarium mode that when unlocked will display a virtual aquarium on the top screen.