Rainbow Islands Extra

Bubby and Bobby set off to rescue the inhabitants of the Rainbow Islands, who have been turned into Bubble Dragons by the evil Boss of Shadow. They must collect the big gems and mirrors on the ten Rainbow Islands and defeat the Boss of Shadow to return the islanders to normal.

Résumé

Rainbow Islands Extra is a strange update to Rainbow Islands: The Story of Bubble Bobble 2, released by Taito for arcades in 1988.

Although it offers a port of the original Rainbow Islands, the default option is the "extra" mode, in which all the cute and colourful enemies found in the original game are replaced with enemies found in Taito's shoot-'em-up series, Darius.
The story for both modes is the same: Bubby's friends have been captured and turned into Bubble Dragons by Super Skull Monsta, and Bubby needs to save them by destroying the Super Skull Monsta's minions with rainbows and collecting Little Diamonds to get Magical Mirrors needed to break the spell.