Unused sprite of a cactus from the Japanese Super Mario Bros. 2 (known internationally as Super Mario Bros.: The Lost Levels).
In Super Mario Bros: The Lost Levels, Mario and Luigi will not be harmed by the hammers thrown by walking Hammer Bros. as long as they are standing at the left edge of the screen. This glitch is present in all versions of the game.
In the Japanese Super Mario Bros. 2 (also known as The Lost Levels), Mario’s fireballs can pass through corners between diagonally arranged tiles.