"Donkey Kong Junior" is a classic arcade game released for the Atari XL/XE systems in 1983, developed by Nintendo R&D1 and published by Atari, Inc. This action-packed platformer game invites players into a compelling storyline where Mario plays the antagonist, having captured Donkey Kong and locked him in a cage. Players control Donkey Kong Jr., embarking on a rescue mission through four different levels - Vines, Springboard, Chains, and Mario's Hideout - to free his father from Mario's clutches.

Throughout the game, Mario attempts to stop Junior by sending out various obstacles such as Snapjaws, swooping purple birds, and electric sparks. Donkey Kong Jr. can defend himself by dropping fruit on his enemies to knock them out, with the possibility of scoring bonus points for hitting multiple foes with a single piece of fruit. Additionally, Junior can climb faster by grabbing hold of two chains or vines at a time and can jump over enemies to evade them. However, players must be cautious of long falls or water hazards, as these will result in the loss of a life.

The game was praised for its challenging gameplay, especially on the Atari XL/XE versions, which were noted to be more difficult than the ColecoVision version, particularly on the second screen​​​​. Upon completing all four levels, the game restarts at a higher difficulty level, offering players a relentless challenge and endless entertainment.