Castle of Illusion starring Mickey Mouse (known in Japan as I Love Mickey Mouse: Fushigi no Oshiro Daibouken, or "I Love Mickey Mouse: Great Mysterious Castle Adventure", and in the Japanese title screen as Castle of Illusion: Fushigi no Oshiro Daibouken) is a 2D side-scrolling platformer developed and published by Sega for the Sega Genesis on November 20, 1990 in Japan, on December 1990 in North America, and on March 1991 in Europe. It is the first in a series of Sega-produced games starring Disney mascot Mickey Mouse (known as the "Illusion" series).
As Mickey, players must embark on an adventure through the evil and mysterious Castle of Illusion to rescue Minnie Mouse from the evil witch Mizrabel, who plans to steal Minnie's youth. To do so, he must find the seven Gems of the Rainbow (guarded by the Masters of Illusion) hidden within the magical worlds (including an enchanted forest and a toy-box) scattered throughout the castle. The game's Practice difficulty changes the goal, in which Mickey must find three gems (collected by completing a particular level from the game's first three worlds) that would make Mizrabel see beauty in herself.
The game was later remade for the Sega Master System and Sega Game Gear throughout 1991, featuring redesigned levels and simplified graphics (as well as different enemies, items, and bosses), as well as completely changing one of Mickey's attacking mechanics from flinging apples (and other items previously collected) to picking up and hurling larger solid objects found throughout each level (such as indestructible barrels, which double as a puzzle mechanic). The Game Gear version was a launch title in North America, and was released in Japan as Mickey Mouse no Castle Illusion.
The game also received a "sister game" starring fellow mascot Donald Duck, titled QuackShot starring Donald Duck. Both games later received a successor as World of Illusion starring Mickey Mouse and Donald Duck, and were bundled together as both a 1996 European Sega Mega Drive compilation (The Disney Collection) and a 1998 Japanese Sega Saturn compilation (Sega Ages: I Love Mickey Mouse: Fushigi no Oshiro Daibouken / I Love Donald Duck: Guruzia-ou no Hihou).
The game later received a full remake on September 3, 2013 (almost 23 years after the original game's release) as a downloadable title for the Xbox 360, PlayStation 3, and PC. Developed by Sega Studios Australia, under supervision of the original game's director, Emiko Yamamoto, the remake retains the story while featuring a variety of new gameplay mechanics (such as transitioning between 2D and 3D platforming) and a spoken narrator. The original game was re-released digitally for the PlayStation 3 (for owners who pre-purchased the remake after August 20, 2013) and was included in the North American and European versions of the 2019 Sega Genesis Mini microconsole.
As Mickey Mouse travels through these wacky and dangerous worlds, he will have to defeat a variety of enemies to advance. To attack enemies, Mickey can stomp on them, or fling apples and marbles at them, which can be collected throughout the game. Mickey Mouse can also collect icons that restore health, add extra lives, or boost the score.