Donkey Kong begins with the four levels found in the original arcade game, but with enhanced graphics and play mechanics (for instance, falling off a girder is no longer instantly fatal, and Mario can let go of the Hammer prematurely to jump if necessary, catch it again and continue using it until it runs out). Like in the original, the player's goal in these stages is to reach Pauline, who is in top of the structure. The level pattern follows that of the original arcade release (Girders - Conveyor Belts - Elevators - Rivets). After these four initial stages are completed, the usual arcade ending begins, but after a few notes of the "victory theme" Donkey Kong revives, grabs Pauline again, and takes off with her, with Mario giving chase. The player is then presented with 97 additional stages spanning nine worlds, for a total of 101 stages.
The subsequent levels follow a completely different game mechanic in which the player must guide Mario through each level to locate a key. He must pick it up and carry it to a locked door elsewhere in the stage. On every fourth level, the player must confront Donkey Kong himself and reach Pauline, like in the original levels. After the fourth level is cleared, a short cutscene is shown depicting a player's abilities that may be needed for the upcoming levels, or to introduce new kinds of traps. At this point, players are allowed to save their progress, including their time for each level or for the total set.