Rainbow Islands, subtitled The Story of Bubble Bobble 2, is a sequel to Bubble Bobble starring Bubby and Bobby, the human forms of the first game's protagonists, Bub and Bob. Bubby and Bobby must rescue the denizens of Rainbow Islands, who have been imprisoned and turned into Bubble Dragons by an evil villain. As opposed to Bubble Bobble, where enemies were trapped in bubbles, to defeat enemies in Rainbow Islands the player must shoot rainbows at them. (bubblebobble.fandom.com)