Here is the full list of all 12 Castle of Illusion Starring Mickey Mouse achievements worth 400 gamerscore.
Defeated Mizrabel and rescued Minnie.
Collected all the Magic Playing Cards.
Collected all of Donald's Chili Peppers.
Completed all Castle Statues.
Found all the Magic Diamonds.
Completed a stage in Time Attack mode.
Found 50% of all Magic Diamonds.
Broke the illusion of 25 enemies with projectiles.
Completed a Castle Statue.
Bounced on 7 enemies in a row without touching the ground
Broke the illusion of 75 enemies.
Unlocked a Castle Painting.