Super Mario Brothers: The Lost Levels is a special version of Nintendo's Super Mario Bros, first released in Japan for the Nintendo Family Computer.

SMB2:LL does not have a two-player game. Instead, one may play as Mario or as Luigi. The game is a little harder than the original Super Mario Bros, due to a slightly modified game engine, and more difficult levels. It was not released in the United States until its inclusion in Super Mario All Stars. After that, it was released in Super Mario Deluxe, though hidden and without Levels 9 and A-D.