List of Super Mario Bros. 3 pre-release and unused content

The following are the beta elements of Super Mario Bros. 3. For beta elements of the Game Boy Advance remake, Super Mario Advance 4: Super Mario Bros. 3, see here.

Early ideas
Designers considered a power-up to turn Mario into a Centaur (half-man, half-horse), although this was rejected before being implemented into the game.

Early builds
As seen in early screenshots, Koopa Troopas and Hammer Bros. were going to host two mini-games. The minigames were a Question Block and a Dice Block game respectively, which also would have marked the first Mario game to have the Koopas standing instead of all fours. These minigames and their hosts seem to have been replaced by Toad. An early build of the game was previewed in a promotional VHS tape coming with the September 1988 edition of the magazine Famimaga. The preview shows several levels unused in the final game, a different sprite for the Wooden Block and a slightly different status bar.

The back of the box of some early copies of Super Mario Bros. 3 depicts Mario traversing a hilly grassland stage with many Para-Beetles and two Note Blocks. This particular stage is not any of the lost ones present on the cartridge, nor is it in the final game. These boxes also feature a beta map of Grass Land.

Enemies
There were going to be two new enemies called Gold Cheep Cheep (a golden version of a Cheep-Cheep), and Green Para-Beetles (green colored Para-Beetles). The Gold Cheep Cheeps would have be seen in groups and swim faster than regular Cheep-Cheeps. The Green Para-Beetle flies faster than the normal varieties.

Objects
The game's graphics reveal an item-sized Toad icon among some of the game's suits; this is interpreted by several as a sort of "Toad Suit", although it makes no changes to gameplay when granted to Mario. This has been recently proven to actually be a Hammer Suit with palette errors, and appears clearly in a "?" block in 7-8, giving Mario the Hammer Suit.

A set of blocks, with a large "?" block surrounded with smaller "?" blocks was also a scrapped object. This may have been something used in a bonus game/area.

Levels
Fifteen unused levels exist within Super Mario Bros. 3. Some of these are unique, while others bear much resemblance to levels seen in the final version.