Kirby Tilt 'n' Tumble was released for which Nintendo handheld?

Kirby Tilt 'n' Tumble was released for the Game Boy Color.

Nintendo released the motion-focused action puzzle game in Japan on August 23, 2000, followed by North America on April 9, 2001. Its cartridge contains built-in accelerometers, allowing the player to guide Kirby by physically tilting the handheld rather than relying only on the directional pad.

The unusual hardware explains why the game is specifically associated with the Game Boy Color, not merely the broader Game Boy family. The cartridge was also molded in a distinctive translucent pink color in North America, echoing Kirby’s appearance. Because the Game Boy Color is backward compatible with many original Game Boy games, players sometimes confuse the systems, but Tilt 'n' Tumble was designed as a Game Boy Color title.

The game’s development began with a prototype called Koro Monkey, which featured a monkey before the character was changed to Kirby. A planned sequel was later shown but ultimately canceled.