The Kirby series has used a crescent moon as a door to a secret area filled with items on multiple occasions:

• In Kirby's Dream Land, the moon can be entered on Stage 4, Bubbly Clouds.
• In Kirby's Adventure, the same moon can be entered on Stage 6 of Rainbow Resort, which is a stage designed as an abridged remake of the first game.
• In Kirby Super Star, the moon can be entered in the Bubbly Clouds level of Spring Breeze, a sub-game that also acts as an abridged remake of the first game.
• In Kirby Triple Deluxe, the moon in Stage 6-1 leads to a HAL Room.
• In Kirby: Planet Robobot, the holographic moon on Stage 6-8 leads to a rare sticker.