Donkey Kong Jr. for the Atari 7800. Donkey Kong Junior (Jr.) arcade game for the Atari 7800 video game system. Based on the popular arcade game, Donkey Kong Jr. is the sequel to the immensely successful Donkey Kong. Players play as Donkey Kong's son, Junior, and rescue his dad, who has been kidnapped and imprisoned in a cage by Mario. Players use their jumping and climbing abilities to clamber up vines and chains, gather vital fruit and keys, and open the cage to free their father. Make sure to avoid the pesky birds, nasty electric sparks and creepy chompers.