The basic premise of the game is that each level is an island which is slowly sinking into the sea. The player must therefore get to the top of each level, by jumping on platforms and making use of the game’s most distinctive feature: the ability to produce solid rainbows, which are used both as platforms to stand on, and as a weapon.
One of the features which sets this game apart from many others (and has no doubt been responsible for the game’s popularity) is its ‘hidden depths’. While initially appearing to be quite a simple game, Rainbow Islands in fact has a vast number of secrets for the player to discover, including secret levels, secret power-ups and riddles. Because of these elements, completing the game properly requires a large amount of dedication from the player. The scoring system also has secrets, which allow vastly higher scores to be achieved than normal.
Rainbow Islands Extra Version is a modified version of Rainbow Islands; the game is exactly the same except the stages’ enemies and bosses appear in a different order (much like Bubble Bobble’s Super Mode). Rainbow Islands Extra was released in limited quantities in the arcade. The game was also included as a mode in the Sega Mega Drive version of Rainbow Islands