Even though Ability Planet isn't technically a real stage within Story Mode - since there are no Rainbow Puzzle Pieces to be found and the level itself cannot be cleared - it serves as a extra incentive that all players can ultimately obtain. Unlike other extra stages found in Story Mode outside of Extra Planet Z, you actually cannot unlock Ability Planet by activating a Hidden Switch. Instead, in order to unlock this extremely rare stage, you must actually complete the entire Story Mode. After you do, you will unlock Ability Planet, where Kirby can learn every Copy Ability within the game while taking part in a Special Challenge Room!