Mario vs. Donkey Kong is a 2004 puzzle-platform game developed by Nintendo Software Technology and published by Nintendo for the Game Boy Advance. The game is the spiritual successor to Donkey Kong, which was released in 1994 for the Game Boy.

The gameplay revolves around a combination of platform and puzzle elements. Players control Mario through small sets of challenges to find a key and rescue Mini-Marios from Donkey Kong.

Mario vs. Donkey Kong received positive reviews, particularly for its gameplay and graphics. It spawned a franchise of the same name with the first sequel, Mario vs. Donkey Kong 2: March of the Minis, released on Nintendo DS in September 2006. A remake for the Nintendo Switch was released in February 2024.

In Mario vs. Donkey Kong, the player assumes the role of Mario, who is pursuing Donkey Kong through a toy factory in order to retrieve several stolen Mini-Mario toys. The game, a puzzle platform game, plays similarly to the Game Boy Donkey Kong game, giving Mario a vast set of different athletic moves, including a handstand, a sideways somersault, and a triple jump, all of which can be used to maneuver platforming stages in various different ways. There are several different environments, ranging from a lava environment to the classic construction site, and there are five different types; in the first, and most common, Mario has to pick up a key and take it to the locked door, and then find and pick up the Mini-Mario toy at the end of the level. The second type is where Mario must guide six Mini-Mario toys to the Toy Box, while protecting them from dangerous environments. The third type is the boss level, where Mario must fight Donkey Kong in order to proceed to the next world. The fourth type is the Plus Level, where Mario must activate one Mini-Mario in the level, which is holding a key, and take it to the door. The Plus levels are overall designed to be more difficult than the main levels. The fifth type of level is the Expert levels. The Expert levels can be accessed after beating the main worlds, and after collecting enough stars in the main and Plus levels. In the Expert levels, Mario must get the key and lead it to the door, much like the main levels, but the Expert levels are the hardest levels in the game. Getting through the door beats the level in Plus and Expert modes, rather than sending Mario to a second part.

Mario is the owner of Mario's Toy Company, a toy enterprise in which he sells a series of small wind-up toys called "Mini-Marios". After seeing a television advertisement for the Mini-Marios, Donkey Kong immediately falls in love with the toys and sets out to the toy store to get some for himself, only to find that they are sold out. Furious, Donkey Kong breaks into Mario's toy factory across the street and steals all of the Mini-Marios, prompting Mario to chase after Donkey Kong to get his toys back.

Mario travels in pursuit of Donkey Kong, rescuing the Mini-Marios and battling Donkey Kong several times along the way before retrieving all of the toys. Upon realizing that all the stolen toys are now gone, Donkey Kong kidnaps all of Mario's Toad workers and imprisons them on the tower of a big building. Mario climbs to the top of the tower, rescues the Toads, and battles Donkey Kong once more, after which Donkey Kong falls onto a truck containing a shipment of new Mini-Marios. Donkey Kong then promptly steals this set of toys as Mario pursues him once again to reclaim them.

Following another cat-and-mouse chase, Mario gets back all but six of the captured Mini-Marios, which Donkey Kong holds captive and guards with a large robot mech. Mario fights Donkey Kong one last time, destroying Donkey Kong's mech and finally getting back the rest of the toys. Upon noticing Donkey Kong upset, Mario decides to give Donkey Kong a free Mini-Mario toy. After finally getting what he has wanted all along, Donkey Kong, Mario, and the remaining Mini-Marios all rejoice together.

The game is an evolution of Donkey Kong Plus, a title on display at E3 2002. During the show, Plus had a feature that allowed players to design and save their own levels on the GameCube, then copy them to the Game Boy Advance using a link cable. It was essentially an updated version of Donkey Kong '94, but the game had disappeared by the following year. It was replaced with the pre-rendered graphics and gameplay additions of Mario vs. Donkey Kong. The Create-a-Level feature was removed from this version but appears in its sequel. The level editor still exists within the game's programming and can be enabled through a modification.^{[citation needed]}