Bubble Bobble Part 2 was released by Taito in 1993. Two versions of this game were developed independently from each other and for different consoles - one for the NES and the other for the Game Boy. Each game was given a different storyline, but it is arguable that they do relate to one another.
This debate is based on the characters' identities. Although the NES game's manual states that the two characters are Bub and Bob from the original Bubble Bobble, they are referred to as Cubby and Robby in the bonus rounds, which are the characters used in the GB port.
This game employs the same style of gameplay as it's predecessor, as well as a similarly large number of levels.
Because of its late release on the NES, Bubble Bobble 2 is quite rare.