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