Here is the full list of all 12 Castle of Illusion Starring Mickey Mouse achievements worth 400 gamerscore.
Broke the illusion of 25 enemies with projectiles.
Broke the illusion of 75 enemies.
Unlocked a Castle Painting.
Collect all the Magic Playing Cards.
Collect all of Donald's Chili Peppers.
Complete the Game.
Complete a Castle Statue.
Complete all Castle Statues.
Find 50% of all Magic Diamonds.
Find all the Magic Diamonds.
Bounce on 7 enemies in a row without touching the ground
Complete a stage in Time Attack mode.