Rainbow Islands: The Story of Bubble Bobble 2

Rainbow Islands is the sequel to Bubble Bobble, with Bubby and Bobby setting out to save a chain of islands from the Dark Shadow. You fire rainbows that hit enemies and double as platforms. Jumping on a rainbow sends it crashing down onto anything underneath. Each island has four rounds, and you have to climb to the top before the rising water catches you. Collecting the seven coloured diamonds in the right order unlocks secret rooms.