List of Super Mario Kart pre-release and unused content

This is a list of pre-release and unused content for the game Super Mario Kart.

Early Iteration
The game was initially developed as an original IP and starred a "guy in overalls". The game was retooled as a Mario spinoff after the development team replaced the player character's sprite with Mario and decided that they liked the look of the game better that way.

Prototype cartridge
A user on the Digitpress forum bought a prototype cartridge and showcased its differences in a thread.

Visuals

 * The Cheep Cheep sprite is upside-down.
 * The cup selection screen lacks a border.
 * The X on Lakitu's flag when the player drives the wrong way is not present.

Sound

 * Vanilla Lake 1 has a different theme, which does not appear in the final build.
 * During the Rankings screen after completing a race, Donkey Kong Jr.'s theme is different than the final version.
 * The Bowser's Castle theme is played in Rainbow Road.
 * Most sound effects are different or have a different pitch.
 * Some themes have slightly different instrumentation and rhythms from the final version.

Content

 * The prototype has animations when ranking 2nd or 3rd place in a championship, something which does not happen in the final game. Scoring 2nd shows a Super Koopa looping over the podium and then getting hit by the winner's champagne cork, while the 3rd place animation has a group of Koopa Paratroopas flying over the podium, the last of which is also hit by the cork.
 * The 150cc mode is not present.
 * The "Replay" feature for Time Trial mode is absent.
 * Battle Course 3 is set in Choco Island and has a different layout.
 * Rainbow Road is narrower.
 * The player cannot drop the Green Shell item or throw the Banana Peel.

April 13, 1992 Prototype build
On July 24th, 2020, a prototype build for Super Mario Kart dated April 13, 1992 was leaked and many differences can be found between the prototype and the final game.

Visuals

 * The X on Lakitu's flag when the player drives the wrong way is not present.

Sound

 * The title screen and Vanilla Lake have different themes, both of which do not appear in the final build.
 * The Donut Plains theme has a different pitch compared to the final build.
 * The Koopa Beach theme is shared with the Choco Island courses.
 * The theme used for battle courses in the final build is played in Mario Circuit, Ghost Valley, and Bowser's Castle courses.
 * Battle courses use the themes of the respective courses they are based off of instead of the normal theme used for battle courses in the final build.
 * The title screen theme is played during the ranking screen at the end of a championship.
 * During the Rankings screen after completing a race, Donkey Kong Jr.'s theme is different than the final version.
 * Some themes have slightly different instrumentation and rhythms from the final version

Content

 * The 150cc mode is not present.
 * Many courses, including battle courses, have different layouts compared to the final build.
 * The drifting mechanics work differently in this build, as there is no jumping before drifting.
 * The course orders of various cups are different.
 * A Choco Island 3 course can be found in the Special Cup instead of Rainbow Road.
 * Battle Course 1 in this build is the Battle Course 4 of the final game, setting in Donut Plains.
 * Battle Course 2 in this build is the Battle Course 3 of the final game and has more ice blocks.
 * Battle Course 4 in this build is the Battle Course 2 of the final game.
 * Battle Course 3 is set in Choco Island and has a different layout.
 * Vanilla Lake 1 does not load in and crashes the game.
 * An unused driver was found in the game's files. The driver looks like a generic racecar driver. Unused sprites show the character in both a normal kart and what appears to be a bumper car.