The Bugs Bunny Crazy Castle

Honey Bunny has been kidnapped by Wile E. Coyote, Yosemite Sam, Daffy Duck, and Sylvester, and Bugs must travel through 80 levels in order to save her. To get past each level, Bugs must collect all 8 carrots in each level.

Résumé

The Bugs Bunny Crazy Castle for the Game Boy is a port of the game called Mickey Mouse, which is, in turn, a port of the Famicom Disk System game Roger Rabbit (known in the West as The Bugs Bunny Crazy Castle, NES version).
It is a portable port of the first Crazy Castle game.