What is "fangame"

n. (context fandom English) A video game created unofficially by fans of an existing game, and based on it.

Fangames are video games made by fans based on one or more established video games. Many fangames attempt to clone or remake the original game's design, gameplay and characters, but it is equally common for fans to develop a unique game using another only as a template. Though the quality of fangames has always been variable, recent advances in computer technology and in available tools have made creating high-quality games easier.