Alex Kidd in Miracle World is a platform game for the Master System. It was released in Japan on November 1, 1986, followed by North America in December 1986, with Europe in September 1987, plus South Korea in October 1988, and Brazil in 1989. It was later built into many Master System and Master System II consoles. A remake by Merge Games and Jankenteam, titled Alex Kidd in Miracle World DX, was released on June 22, 2021.

A platformer is a sub-genre of action video games in which the core objective is to move the player character between points in an environment. Platform games are characterized by levels with uneven terrain and suspended platforms of varying height that require jumping and climbing to traverse. Other acrobatic maneuvers may factor into the gameplay, such as swinging from vines or grappling hooks, jumping off walls, gliding through the air, or bouncing from springboards or trampolines.