Rainbow Islands

Rainbow Islands (レインボーアイランド) is a 1987 arcade game developed and published by Taito. The game is subtitled "The Story of Bubble Bobble 2" and is the sequel to Taito's hit game Bubble Bobble from the previous year. It is the second of four arcade games in the Bubble Bobble series (followed by Bubble Symphony and Bubble Memories, but itself has two direct sequels: Parasol Stars and Bubble Bobble Part 2). The game was ported for numerous home computers and consoles.

The main characters are Bubblun and Bobblun, the protagonists of Bubble Bobble (known as "Bub and Bob" in the western releases). However, in this game they appear in their human forms as "Bubby" and "Bobby", as opposed to the "bubble dragons" of the first game (following on from the first game's true ending). Also unlike the first game, players must now "alternate" (i.e., take turns), with player one as Bubby (green shirt), and player 2 as Bobby (blue shirt) (as with the first game).

The game is set on a chain of ten islands, each one with a different theme. Each island provides four rounds of gameplay, and once these are complete the player moves to the next island in the chain. In each round the player must get to the top before the sea level rises and kills them. The islands get progressively more difficult, with enemies moving much faster on the later ones. These are depicted on a map screen before the start of each island. The three secret islands are not visible until all 7 big diamonds are collected. To get a big diamond, the player must collect seven different-coloured small diamonds on the island and finish it. The small diamonds are found by beating enemies by dropping a rainbow on them from above or beating them with various power-ups. After collecting the small diamonds, a word "NICE" will appear. Most consumer versions of the game completely lack the secret islands.

Players can release rainbows that act as both weapons against the enemies and as a makeshift platform. By jumping on them, they fall down beating any enemies below it. Collecting power-ups increases the player's speed, the speed of the rainbows and how many are spawned. If players take too long in a level, water will start to rise up from the bottom of the stage.

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.

Extra version
Rainbow Islands Extra 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). While layouts of the islands remain exactly the same as in the original version, they are occupied by a set of enemies from a different island. The order in which you encounter the enemies is as follows: In addition, the bosses were made more difficult by adding more variety to their behavior. The secret rooms are still present, but the codes they provide are incomplete. Only the first character and one other character of the codes are shown, and the other character is determined by something that players must determine through a series of complicated hints (see the page for more information). All of the title screen codes have been altered. More bonus points are awarded to players who reach the secret rooms and don't collect the permanent power-ups.
 * 1) Darius Island enemies (and music) on Insect Island
 * 2) Magical Island enemies (and music) on Combat Island
 * 3) Dragon Island enemies on Monster Island
 * 4) Doh Island enemies (and sound effects) on Toy Island
 * 5) Insect Island enemies on Doh Island
 * 6) Monster Island enemies on Robot Island
 * 7) Toy Island enemies on Dragon Island
 * 8) Robot Island enemies on Magical Island
 * 9) Combat Island enemies on Darius Island
 * 10) Bubble Island remains the same as in the original version

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. The arcade version was licensed to Romstar for North American manufacturing and distribution.