Cheats for Kirby: Nightmare In Dreamland (GBA)

Extra mode:
Successfully complete adventure mode with a 100% rank to unlock the "Extra mode" option at the adventure mode menu.

Boss mode:
Successfully complete the game to unlock the "Boss Mode" option at the mini-game menu.

Meta-Knight mode:
Successfully complete extra mode with a 100% rank to unlock the "Meta-Knight" option at the mini-game menu.

Ball ability:
The Ball ability may seem useless at first glance, as it is only a form of moving around a level. However, while Kirby is flashing as a ball, he is invincible and does a ludicrous amount of damage to enemies in his path. This makes it possible to destroy King Dedede in five hits. However, you will be vulnerable momentarily when you hit the ground. Jump into Bosses at such an angle that you will not land "inside" them.