The game starts in a place called Wasteland. While Mickey is watching TV, Oswald appears and needs Mickey's help for the final time. The problem is not that Oswald is being attacked by the Mad Doctor this time, it's that he is being attacked by a witch named Mizrabel who has kidnapped Mickey's girlfriend, Minnie Mouse. Mizrabel is the returning villain from Sega's Castle of Illusion: Starring Mickey Mouse.
Mickey goes out to stop Mizrabel by using a blue magic paintbrush, with this weapon, nothing will get in Mickey's way, so when Mickey gets to the floating castle, he meets up with a small green cricket with a umbrella named Jiminy Cricket (Pincchio's best friend in the classic Disney Flim Pincchio) and he tells Mickey that hasn't seen Minnie, but he has discovered a few things about the castle. The castle is now controlled by Mizrabel. Jiminy and Mickey go into the castle and see Minnie standing there. Before she can be reached, other Disney villains appear: Uncle Scar (Simba's enemy), the Evil Queen (Snow White's Enemy), Gaston (Beast's and Belle's arch-nemesis), and more. The villains block the way while Mizrabel guards Minnie from being rescued.
After a conversation with the enemies, it's time to start the adventure.
When you start this first level, it's been based off by the castle parts in the original. The Toons you rescue in this level are the Beast (from Beauty and the Beast) and Scrooge Mcduck (from Ducktales).
Next, you don't go to the next level yet, you check on a room with a heart, this is the Toon Heart Power room, this shows how much Heart Power it has so Mickey can access new areas in the castle, but it only increases every time when you rescue a Toon in the levels. Leave and go to the brand-new level, London Skies, a level based off of Peter Pan.
Make your way to the top and encounter the London's clock which was seen at the beginning and end of the Peter Pan film. The Toons rescued in this level are Wendy Darling, Michael Darling (both from Peter Pan; Michael only appears in the level when receiving a new quest from his old and tall sister Wendy), and Goofy (Mickey Mouse's friend).
Next is the Neverland Jungle, a home of wild kids called the Lost Boys (Peter Pan's gang; Peter is the leader). Make your way through the Jungle to encounter their second leader, John Darling. The toons you rescue in this level are: Tinkerbell (from Peter Pan; if you rescue her on your first visit or other visits, she's been taken to Peter Pan's room along with his friend Cubby), Raunpzel (from Tangled), and John Darling (from Peter Pan). At the end of the level, Captain Hook (Peter Pan's enemy) appears, after a short talk, he leaves.
The next level is the Jolly Roger where in the original film Peter Pan battles Captain Hook to a finale while the kids beat up his angry pirate henchmen, including Mr. Smee, the first mate. You begin on a brown pirate ship with nothing except for pirates that throw barrels at you. The Toons rescued here are Peter Pan and Mr. Smee (who only appears after you receive a quest from his pirate captain leader, Captain Hook).
The next thing to do is face the boss, Captain Hook, he should be really easy if you know how to dodge his cannonball attack.
Jafar can be tougher though, because he transforms into a huge Cobra and tries to squash you with a headbutt attack. After two attacks, the Genie hand platform disappears. This makes it more difficult because there's lava below you. You will have to re-paint the hand he destroyed.
After you defeat Captain Hook, he is un-brainwashed and becomes Mickey's friend.
In the next world, it has same creatures, but different ones, the next level is Castle west Hall. The Toons you rescue here are Rajah (from Aladdin). Rajah is Princess Jasmine's pet. He cannot talk, similar to Mickey's dog, Pluto. Donald Duck (one of Mickey's best friends) and Snow White in the next level, you arrive in a Town called Argabah where brainwashed guards controlled by the red Cobra Wizard Jafar patrol the city preventing from anyone entering it! The Toons rescued here are Aladdin and Cinderella. At the end, you see Jafar blocking the exit. After speaking with him, exit the level.