Donkey Kong Jr. is a 1982 arcade-style platform video game by Nintendo. It first appeared in arcades, and, over the course of the 1980s, was later released for a variety of platforms, most notably the Nintendo Entertainment System. The second installment in the Donkey Kong arcade series. The game's title is written out as Donkey Kong Junior in the North American arcade version and various ports to non-Nintendo systems. Its eponymous star, Donkey Kong Jr., also called simply Junior or abbreviated as DK Jr., is trying to rescue his father Donkey Kong, who has been imprisoned. Donkey Kong's cage is guarded by Mario, in his only appearance as an antagonist in a Nintendo video game. This game is the sequel to the video game Donkey Kong, which featured Mario as the hero and Junior's father as the villain.