In the beginning video, Donkey Kong is at home channel-surfing. While flipping through channels, DK notices an ad about the new Mini Mario Toy. Right away, he decides to get his hands on as many as he can, so he steals them from Mario's Toy Factory. Now, Mario has to get them back.

Mario must find the key then rescue a Mini Mario in six levels of each world. In the seventh level, Mario must guide all the Mini Marios he collected through the letters T, O, and Y and into the toy box. The eighth and last level pits Mario against Donkey Kong. There are many enemies and obstacles to avoid, including Bob-ombs, Shy Guys, Boos, trash cans, fireballs, and Thwomps.