Ability Room
During game play, activate all the warping mirrors.
Arena Mode
Collect 100% of the treasures during game play.
Defeat Kracko
Get the Tornado ability before you get to him. When you reach him, hold B. Kirby will spin and go up. While spinning, keep hitting Kracko. Keep doing this until his life is gone. You can also do this with other Bosses.
Boss Rush Mode
Get 100% on a file.
Different Kirby Colors
Find cans of Spray Paint spread throughout the game.
Open the Power Center
Find and hit all of the Portal Switches in the different areas.
Sound Test
Find the CD Treasure (Find Musical Scores to unlock new tunes in it).
Use Metaknight's Sword
Defeat the final bosses.