|“||To open a chest, you need a key. But know this. If you drop a key, it will vanish.”|
|— Daroach • Kirby Mass Attack|
Keys have an extremely minor role in this game. After Kirby defeats Whispy Woods, Kracko, or Poppy Bros. Sr., a key with a star-shaped handle will appear and spin around. If Kirby falls down to the Warp Star before he can grab it, he will travel to the top level of whichever Pinball Land he is in and will have to return to the key's location. He will not have to fight the boss again.
When Kirby touches the key, two more Kirbys will appear and do the Kirby Dance. He will return to the Pinball Land selection screen and be unable to return to that Pinball Land. Once the player acquires all three keys, a Warp Star will appear, and can take Kirby to King Dedede.
Though rather uncommonly seen, keys appear as items in Kirby Tilt 'n' Tumble. If the player picks one up, he/she can open locked doors. Keys are sometimes found in Treasure Chests or guarded by enemies such as Blockbots.
|“||Secret stage available”|
|— Treasure description • Kirby: Squeak Squad|
In Kirby: Squeak Squad, Secret Door Keys (called Hidden Door Keys in the Collection Room) appear as collectible treasures. They are found in every level except for Gamble Galaxy, and unlock a secret stage in their respective levels.
- 1-4: Third Treasure Chest
- 2-5: Third Treasure Chest
- 3-4: Third Treasure Chest
- 4-4: Third Treasure Chest
- 5-4: Third Treasure Chest
- 6-4: Third Treasure Chest
- 7-4: Third Treasure Chest
In Kirby Mass Attack, keys are common items that open treasure chests. They can be held by Kirbys and open the chests. Buzzybat and Skullseer have special keys that can open mid-boss doors in Volcano Valley. Skull keys also appear, which transport the Kirbys to a dimension of Skullys and can unlock skull chests.
There are no treasure chests in this game, so keys (called Lock Keys) serve to open doorways only. Key Dees hold Lock Keys and attempt to run away with them. The character holding a Lock Key is limited to a single jump, making platforming trickier, as well as defense, which only allows the character to run from danger unless he has protection otherwise. If either a Hunter Scarfy or a red Degout is nearby, it will transform and attack the character holding the Lock Key. Lock Keys expire after a time limit, and will be destroyed instantly if they touch lava or spikes. Some Lock Keys will respawn if destroyed, but others will not. Like other carry items, Lock Keys can be carried through doors.
Kirby is given a Lock Key upon entering the door to the Item Challenge.
Lock Keys in Kirby's Return to Dream Land work similarly to the keys seen in Super Smash Bros. Brawl’s Subspace Emissary mode.
Lock Keys reprise their role from in Kirby's Return to Dream Land; they again serve to open locked passageways. New to this game are Key Doors with large locks on them—when Kirby approaches one with a Lock Key in hand, the lock will break and the hero will be able to enter the door. Several puzzles require Kirby to carry a Lock Key to a door while dodging hazards in a Tilt Gondola.
Keys appear as living creatures in this game. Each has a brown faces, gold eyes, gold ears, and a ruby. When Kirby touches one, it will follow him until he reaches a locked door, which it will immediately open. Enemies called Grinkeys transform into ordinary keys when defeated.
Keys function the same way as in Kirby's Return to Dream Land. When preparing to toss one, Kirby can angle his throw. Two keys with a red or blue light appear in one room on Planet Misteen in Story Mode, as well as in Dimensions II, III, and IV in the Heroes in Another Dimension mode. Each key unlocks a door that matches its respective color.