We could not avoid starting from this game, seeing that Raine was born to emulate "Rainbow Islands".

After having taken humans aspect, and after having won against Super Drunk in Bubble Bobble, the story continues with Rainbow Islands, the Story of Bubble Bobble 2.
Bub and Bob, in this adventure, have to free Rainbow Islands from different kind of enemies and huge monsters at the end of each stage (as in screenshot at the top). Each island contains four levels. At the end of the fourth level of each island there is a boss that you must kill.

Our hero is armed with a Rainbow that can be used to hit enemies (you can kill them also crushing the rainbows above their head), and to create bridges to walk on (screenshots below): you can climb the rainbows along the floor, and, if you keep pushing the "JUMP BUTTON", you can jump on the rainbows without crushing. Climb and arrive at the goal point, which is at the last floor.
Hit enemies can turn either into colored diamonds, other useful objects or bonus points.
If you pick up all diamonds, one of each color, you'll get an extra life (as in screenshots at the top).

While you are walking and jumping trough the screen you can find pieces of fruits, sweets, Jewels, etc., and by picking them up you'll get either points, special extra rainbowing power or speed, such as:

red shoe: fast running
red potion: makes extra rainbow (maximum of three)
yellow potion: makes rainbows faster
yellow star: 5 stars fire upwards to kill enemies
red star: 16 stars fire upwards and downwards to kill enemies

Well, there are lot's more, find them out yourself!
Some of the various objects are invisible, but, hit by the rainbow by chance, they'll materialize.

In Extra Version (1988), gameplay is the same as the original, except for stages sequence order and for sound.
Jumping Islands is a bootleg version; the main character has been redrawn, as well as the rainbow, the title screen and other several things (you can see the last two pictures).
Music is the same but tune is different.
Alternate version is exactly the same as original version.
OK, this is a short description of the game, certainly fans of platform games and Bubble Bobble won't miss this game to their game collection! Anyway I'm sure you'll appreciate it. The only doubt I have about this game is that it won't keep you playing for too long, opposite to his predecessor (Bubble Bobble).

The Bonze's comment
The fact that this game was released in a year full of other interesting games from other companies might explain why there were less "Rainbow Islands" cabinets in the arcade places where I lived. And the possible new encryption scheme (using a C-Chip instead of a MCU) might also be the cause why there were less bootlegs for this game (I only saw ONE version of "Jumping" 2 years after in an small cafe). Even if this game is the sequel of "Bubble Bobble", it has almost nothing to do with it: the only remaining thing is the text font! The basic techniques aren't too hard to understand, but you'll need some practise to find how to get a diamond of a specific color. There are only 40 levels in this game, but you will need a lot of time before you see the TRUE ending with all the items and secret codes. Note that I've only played this game with the "Language" Dip Switch set to "Japanese", so the hints of the game weren't much of use to me.