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

Early iteration
The game was initially far more focused on shooting than platforming. Mario could carry weapons (with a rifle and a "beam gun" mentioned as being usable) and the control scheme was different, the up arrow of the was used to jump while pressing  used whatever item Mario carried, or kicked when empty-handed.

The game was initially divided between ground and sky segments, which had Mario riding a rocket (or a cloud in later stages of development) and shooting enemies. The sky-based bonus round of the final game are apparently a remnant of this idea.

The development sketches included in Super Mario All-Stars Limited Edition show that the game initially had screen-by-screen scrolling rather than continous scrolling as in the final version.