Super Mario Kart R

Super Mario Kart R is an early version of Nintendo's Mario Kart 64. Early copies of this game are few and far between as it wasn't available for retail release; however, through the use of the Stop N' Swop feature, some assets pertaining to Super Mario Kart R can be resurrected and placed inside Mario Kart 64, using the A.I. code still on the console's memory. Most features include altered racer profiles, a different title or title screen, music with different instrumentation (or new tracks entirely), an unlockable town track, and new characters.

Magikoopa
The most notable change between Super Mario Kart R and Mario Kart 64 is the addition of a different character, Magikoopa (also known as Kamek), who was eventually replaced by Donkey Kong, and never returned to the series until Mario Kart Tour. His stats were the same as Donkey Kong's, despite his much different appearance. Magikoopa also has one found uncompressed voiceline of his laugh.

Magikoopa's Valley
As well as being a character, Magikoopa was also going to have a stage, being Magikoopa's Valley. This level was an early version of Choco Mountain, containing slightly tighter turns, no rocks, a second bottomless pit, and a Kamek billboard. The music was a different instrumentation of Banshee's Boardwalk, instead of the Yoshi's Valley theme.

Town
An unused town track can also be accessed through Stop N' Swop, being seperate from the normal cups. The town is much bigger, with tight 90 degree turns and a more complex layout. The track ties into a completion percentage stored in the A.I. that changes the level. The more of the game you explore and complete, more buildings and a bigger audience appear in the town. At 100%, the track fully transforms into a daytime city, similar to Toad's Turnpike in design, but still keeping the straighter turns and complex design, as well as they daytime theming.