Kirby And The Amazing Mirror Codes -

Boss Rush mode:
Finish the game with a 100% completion. The "Boss Rush" option will now be unlocked at the main menu.

Power Center:
During game play, activate all of the portal switches. Then, go to the main hub of of Rainbow Route (Area 1). The Power Center door is located in the top left corner.

Sound Test:
Find the CD treasure during game play to unlock the "Sound Test" option in the Treasure list. For more songs, find the Musical Scores during game play.

Kirby Colors:
During game play, find the spray paint to unlock the "Kirby Colors" option in the Treasure list.

Metaknight's Sword:
Successfully complete the game after defeating the final Bosses. Metaknight's Sword will now appear in front of the Magic Mirror.

Ability room:
During game play, activate all the warping mirrors.

Arena mode:
Collect 100% of the treasures during game play.

Defeating Box Boxer:
In Area 3: Cabbage Caverns, you can defeat Box Boxer easily by using the following trick. When you go in to battle him, after you engage him stand just inside the tunnel you came in from. Wait for him to charge up his blast, then inhale it and shoot it at him.