From Wikipedia
The sequel (to Zool), entitled Zool 2, was very similar gameplay-wise, but with more cartoonish and detailed graphics and an attempt at a plot. The nemesis in the game was named Mental Block, and his goal was to stifle the world's imagination, causing rampant boredom.
Zool 2 added the option to play as Zool's female counterpart, Zooz. The two characters played similarly, although there were some subtle differences in their abilities. Most notably, Zool could destroy parts of the scenery that Zooz couldn't, and vice versa, resulting in a slightly different route through the level. The sequel, like the original, also featured several mini games. The most common was a version of Breakout which used Zool's two-headed pet dog as a paddle.
The game also received generally high review scores, but did not make an impact the way its predecessor had despite arguably being the better game as the difficulty level had been curbed and the controls were more responsive. A possible reason for the game's relative lack of attention was that by this stage the system that Zool was most associated with, the Amiga, was in decline as a gaming format.
The Amiga remained the lead format for the second game, but unlike the first it was not widely converted. (...)