Stage 2-12

Stage 2-12 is the final level in the Forest and a boss battle with Donkey Kong in the Game Boy version of Donkey Kong.

Layout
Mario starts below the platform with Donkey Kong, there is a Spring on both sides springing him up to higher platforms with springs springing up to even more platforms with more springs that can spring him up to two platforms where it is the best place to throw Barrels back at Donkey Kong who stands on the middle platform with Pauline on a platform above him with Ladders connected to them.

Enemies

 * Barrels
 * Donkey Kong (boss)

Battle
The battle with Donkey Kong is similar to the battle in the Big-City, except with Springs present. Donkey Kong throws Barrels which, if he simply rolls them from the sides, will make their way down to where Mario was, then continuing rolling until they hit a wall, stand right-side up and can be picked up. If Donkey Kong throws them from the sides, they are sent off-screen and eventually fall down along the platforms in a zig-zag-like manner. If Donkey Kong throws a barrel straight down, once they hit the ground, they turn right-side up and can be picked up at that point. Once Mario has picked up a barrel, he must use the springs to get up to Donkey Kong and throw the barrel at him to damage him. Donkey Kong takes three hits to defeat, so Mario must repeat the process two times to defeat Donkey Kong. Once Donkey Kong is defeated, the level ends but he gets up again, grabs Pauline, and runs off.

Cutscene after level completion
Donkey Kong runs out of the Forest and jumps onto a ship to get away from Mario. He then puts Pauline down and laughs as he knows Mario can't make the jump onto the ship and will fall into the gap. Mario arrives and gets the idea to use the Wire; Donkey Kong, surprised at this, grabs Pauline again and runs while Mario Wire Spins onto the ship and continues chasing Donkey Kong before the cutscene ends. The player is then given lives based on their score.