The game takes place on a number of different worlds, each with a distinct theme. Each world features seven rounds, the last one always hosting a boss that must be defeated to progress to the next world. There are eight main worlds; however, in order to complete the game properly, the player must open a secret door on the final world by collecting three of the Star items - allowing access to 2 secret worlds, themed around "Bubble Bobble" and "Chack'n Pop" that are not initially visible on the main screen. Completing these two lead to the final boss, Chaostikhan (the one responsible for stealing color from the worlds, and supposedly the mastermind behind the previous game's villains) and the true ending. According to an ACE magazine in-depth preview, the Amiga version also has a secret "Nightmare" world.