Mickey Mania has gorgeous visuals for its time, in fact I can vividly remember almost every level from here. The music also has some callbacks from the older Mickey Mouse cartoons (so do the levels). The main issue the game has are a little bit of the controls, and the platforming.
Actually I would say the controls and platforming are fine, but it's more like the hit detection alot of the time don't make sense, and makes the game really fricken hard! Some platforms you think you got the landing but instead you go through them sometimes. Same with enemies where you think you jumped on them or avoided them only to be hit in the strangest way.
If you can get used to the hit detection then you have a serviceable platformer that have amazing sprite work. Just be wary that it may take alot of time to get over the frustrating parts.