The reptilian puffs of smoke that emerge when Mario ground pounds inside a giant Goomba Shoe in the Super Mario Bros. 3 style of the Super Mario Maker series are updated sprites from an unreleased and highly experimental SNES prototype known as Super Donkey.

While Super Donkey is thought to have ultimately evolved into Super Mario World 2: Yoshi's Island, the project was likely tossed around as a Mario or Zelda game at various points in development.

Various development assets associated with Super Donkey, which were uncovered alongside the prototype in the 2020 Gigaleak, include sprites and animations for Link, Mario, and Donkey Kong; the animation files for Link are dated to fall 1990, while Mario's animation files are dated to winter of that year. Additional files for all three characters span overlapping periods in 1991. Link's sprites and animations indicate that Super Donkey was at one point planned to be a side-scrolling Zelda title similar to Zelda II: The Adventure of Link, while Mario's animations imply that the iteration that starred him and Donkey Kong eventually morphed into the 1994 Game Boy title Donkey Kong.