Stage 4-12

Stage 4-12 is the twelfth and final level in the Jungle in the Game Boy version of Donkey Kong. The level is a boss battle against Donkey Kong.

Layout
Mario starts on the middle platform with two platforms on each side for him to jump on. There are four vines on each side for him to climb up to get to platforms on each side. Donkey Kong is on a wide middle platform with Pauline on a platform above him.

Battle
Like the other battles, Donkey Kong rolls and throws barrels down to try and hit Mario, the difference being there are holes in the ground into which rolling or thrown barrels can disappear, therefore Mario cannot grab a barrel unless they are thrown and land on the platforms on the sides. Mario can Handstand to deflect the barrels off his feet to get a barrel; however, even if he does this, he will not be able to reach Donkey Kong as he cannot climb Vines while carrying a barrel. Mario must be on the side platforms to be able to grab a barrel and throw it at Donkey Kong to hurt him, but this time, Poison Mushrooms fall out of broken barrels, so Mario must stay clear of them to avoid being shrunk. Donkey Kong takes three hits to be defeated as in previous battles; once hit three times, Donkey Kong will be defeated and the level will end, but Donkey Kong gets up again and grabs Pauline before he runs away.

Cutscene after level completion
Donkey Kong and Donkey Kong Jr. continue running until they reach bricks. Donkey Kong is on the other side of the bricks while Donkey Kong Jr. is on top. Mario then grabs a Super Hammer to break the bricks as the surprised Kongs flee, with Mario continuing to give chase, leading him to the Desert. The player is then given lives based on their score.