The game starts on a fish bowl containing one randomly customized fish, while Gumball watches with different expressions. As explained in the instructions of the game, the aim of the game is to create a new fish to put into Gumball's fish bowl, by pressing on the green fish plus button.
Pressing the green button will open a menu of options to choose in order to customize the new fish. The customizations include features from different characters of The Amazing World of Gumball. The blue button will randomly customize the features of the new fish. Pressing the green fish bowl button will drop the new fish into the bowl with the already created fish. There is no limit to the number of fish that can be created. The red button will flush all the fish away, while Richard's "Swing Low Sweet Chariot" plays in the background.