List of Super Mario Bros. 2 pre-release and unused content

This is a list of pre-release and unused content for the game Super Mario Bros. 2.

Prototype cartridge
In 2005, a prototype copy of Super Mario Bros. 2 was sold on eBay for $350. It was significantly different from the final release version of the game.

The prototype cart has a SNROM-02 motherboard rather than the final version's TSROM-04. This means that it uses CHR-RAM instead of CHR-ROM and utilizes batteries. This was probably changed because SNROM-02's ROM size is 1 Megabit, rather than TSROM-04's 2 Megabits.

The title and story screens of the prototype use a different color palette, which includes tans and oranges, as opposed to the final version's red and blue scheme. This color scheme returns in Super Mario USA, with a blue sky.

On the prototype version's character select screen, an ellipsis divides the phrase "EXTRA LIFE" from the number of lives remaining. No ellipsis is shown in the final release; however, the ellipsis returns for Super Mario All-Stars remaster. Also, the tableau curtain on the character select screen is slightly flatter than in the final version. Additionally, the prototype offers unlimited continues (similar to the later All-Stars remaster and the GBA remake Super Mario Advance), whereas the final product only offers two continues.

The character's sprites are not significantly different between the two versions, but Mario and Luigi lack scleras (the white part of the eye) in the prototype, and the Princess's scleras are pink. This may be because Mario, Luigi, and Peach's sprites have more colors than the NES hardware can normally handle, and so their scleras actually have to be rendered as a separate sprite from the rest of their bodies.

Several other character sprites are slightly different. For example, the princess has more hair in the prototype. One noticeable inconsistency of the prototype's sprites is that, although all the "item carrying" sprites are finished, the items being carried float at the height the original Yume Kōjō: Doki Doki Panic characters would have carried them at.

In Doki Doki Panic, players could not use the B button to run as this mechanic was almost exclusive to Mario games at the time. This mechanic had not been added when this prototype was compiled. As such, only Luigi and Peach can get to the shortcut in World 1-1.

The prototype used a Magic Lamp to access Sub-space like Doki Doki Panic. The final version uses a Magical Potion.

The underground music in the prototype sounds reminiscent of the Super Mario Bros. 3 underground music, but with different noise waves. It was ultimately reverted to the Doki Doki Panic underground theme in the final product, albeit with a slower tempo and sounding more richer with the usage of the NES/Famicom's DPCM channel. The Invincibility music uses noise-based drums like Super Mario Bros. rather than the final's drum samples. The square waves sound similar the Super Mario Bros. 3 version as well.

In the prototype, the player only has to throw four vegetables at Wart to defeat him. The ending also gave out prize money instead of contributions. Depending on how many times the character died, the player would be rewarded with a different amount of money at the end of the game.