Description taken from Game Boy Advance version of this game

Mario & Donkey Kong revisits the rivalry introduced in Shigeru Miyamoto's first arcade game, 1981's Donkey Kong. As in the coin-op, players control Mario as he climbs ladders, hops on conveyor belts, and jumps over obstacles in order to reach the top of a level. Yet the game also features a number of puzzles as in 1994's Donkey Kong update on the original Game Boy, requiring new techniques and moves, such as swinging on bars, performing headstands and backflips, lifting objects, and activating switches.

The storyline has Donkey Kong stealing Mario's latest creation -- Mario dolls -- when the angry ape learns of the plumber's new toy factory. After all their time together, Mario apparently never considered making a Donkey Kong doll, thus renewing the heated rivalry between the two. Now Mario must run and jump throughout the toy factory to recover as many of the dolls as he can. Mario & Donkey Kong's distinctive visual style uses rendered graphics as seen in Rare's Donkey Kong Country on Super NES. ~ Scott Alan Marriott, All Game Guide