50m

50m is the second level of Donkey Kong. This level has a series of conveyor belts which run along the the second, third and forth floors. This level has hammers to smash Fireballs. There are also ladders, which Jumpman must climb. The top ladders will also disconnect and connect when Donkey Kong beats his chest, which he does instead of throwing barrels like in the first stage. The oil drum in this level is in the middle of the stage, and will produce more Fire to burn Mario. Lastly, because the top floor is a conveyor belt, Donkey Kong will be moving left to right throughout the level. As Jumpman reaches the top, Donkey Kong will take Pauline again and will climb up to the next level.

Trivia

 * This level was removed from NES version due to a memory limit.
 * This is the only level in which Donkey Kong's action doesn't make something appear (25m makes barrels, 75m makes jacks, and 100m makes Fire).
 * This is also the only level where Donkey Kong moves, though technically it is the conveyor belts which are moving.