The game's data contains sprites depicting Kid Klown and Princess Honey from Kid Klown in Night Mayor World, with them filling the roles of the protagonist and damsel in distress, respectively. This indicates that the game was originally devised as a Kid Klown title before being retooled around the Mickey Mouse, Garfield, and Ghostbusters franchises (depending on the region) midway through development. Ironically, Kid Klown in Night Mayor World was itself a retooled English localization of a Mickey Mouse game.

P.P. Hammer and his Pneumatic Weapon level designer Gunnar Lieder claimed that the level layouts of The Real Ghostbusters/Garfield Labyrinth/Mickey Mouse IV: Mahou no Labyrinth were directly copied from P.P. Hammer without their permission, and that Demonware never had any connections with Crazy Castle developer Kemco.

Garfield Labyrinth is a localized version of Mickey Mouse IV: Mahou no Labyrinth where, instead of Mickey having to save Minnie, Garfield has to rescue Odie. However, the ending cutscene of the game was not modified to account for the change from Mickey's girlfriend to Garfield's foil, resulting in the unintentional implication that Garfield and Odie are in a gay relationship as they hold hands surrounded by hearts, frolic in flowers, and travel in a hot air balloon.