Mr. Nutz: Hoppin’ Mad is a side scrolling, 2D platformer game published by Ocean Software for the Amiga and first released in 1994. The game started out as Timet: the Flying Squirrel by a company named Kaiko but was sold before being released. The player character sprite was a slimmer flying squirrel, which was changed to a fluffier red squirrel but some of the level and enemy design remained. [Infos from Wikipedia]
Thanks to Celine for the contribution!