Kagero Mansion

Kagero Mansion (literally "Heat Haze Mansion") was a planned spin-off game in the Kirby series, conceived by Masahiro Sakurai as a hybrid of puzzle and action games with horror elements. Although it was pitched to HAL Laboratory, it never entered development, due to a lack of time and resources while the company was making other Kirby games (such as Kirby Super Star). The game remains an unrealized idea, and it is not known what platform(s) it would have released on. Its existence was revealed by Sakurai in October 2017 during an official interview conducted in recognition of the release of the Super Nintendo Classic Edition microconsole.

The planned story of Kagero Mansion would have involved Kirby exploring a horror-themed mansion while afflicted with a curse that sealed his mouth shut. Without the ability to Inhale enemies, Kirby would have needed to find alternate methods of gaining Copy Abilities, such as by absorbing the fire from a lit candle. Sakurai would have intended the experience to be "completely different from the usual Kirby game."