Bubble Bobble featuring Rainbow Islands is a puzzle game where you play as Bub and Bob, two brothers who must rescue their sister from the clutches of an evil witch. The witch has turned her island into a frozen wasteland and Bub and Bob must navigate through the ice to reach her. Along the way, they'll encounter various obstacles, enemies, and power-ups that will aid them in their quest.
The gameplay involves guiding Bub and Bob through levels, breaking ice blocks to reveal hidden paths, and defeating enemies to collect points. The game also features a unique bubble-shooting mechanic, where players can trap enemies in bubbles to create chain reactions and clear obstacles. As players progress through the game, new abilities and power-ups become available, allowing for increased difficulty and challenge.