Kirby's Adventure
Kirby's Adventure
Attachment
The game contains graphics for an unused 7th stage door. This suggests there may have originally been plans to have 7 stages in at least one hub, but the largest level hub in the final game only contains 6 stages.
Contributed by MeleeWaluigi
Attachment
In the remake of Kirby's Adventure, Kirby: Nightmare in Dream Land, the official Japanese website for the game had many screenshots that were taken at a previous point in development. Poppy Bros. Sr. appears in one. The image shown shows that his sprite was originally going to be similar to his sprite from Kirby Super Star.
Contributed by Ophl
Attachment
According to the Kirby's Dream Collection celebration booklet, a few ideas were cut from the game. Such as Kirby digging holes, turning invisible, multiplying, and even turning into a puddle of water.
Contributed by Ophl
Attachment
Originally there was a cannon icon that would appear whenever Kirby was on a cannon. Even though this was cut from it's original purpose, the cannon icon can still be found by using the Mix ability: it can be seen during the roulette selection of abilities using an emulator's frame-by-frame advance feature. Oddly enough, it remains used in the French version.
Contributed by Ophl
At 6 megabits on the game cartridge, Kirby's Adventure is the largest Licensed NES game.
Contributed by KidDivinegon
The original Japanese commercial for Kirby's Adventure depicted the game's characters made of yarn. This is thought to have inspired the art style of Kirby's Epic Yarn.
Contributed by Boyobmas
The first letters of the world names (excluding the Fountain of Dreams) spell out VIBGYOR, which is ROYGBIV backwards, a mnemonic used for remembering the colors of the rainbow.

• Vegetable Valley
• Ice Cream Island
• Butter Building
• Grape Garden
• Yogurt Yard
• Orange Ocean
• Rainbow Resort
Contributed by irtehmrepic
In Vegetable Valley's second level, there is an easter egg room that can be accessed by moving away from the Warp Star until it disappears. The blocks are stacked to form 'HAL', referencing the game developer's name.
Contributed by Gors
Attachment
The graphics of an unused ability are stored in the game in which Kirby appears to be mini, similar to an ability featured in a much later title, Kirby & the Amazing Mirror.
Contributed by Dazz