Super Mario Bros.: The Lost Levels

Super Mario Bros.: The Lost Levels is a direct sequel to Super Mario Bros. Not to be confused with the western Super Mario Bros. 2, this sequel to Super Mario Bros. is very much an expansion to the original, with many reused graphics and concepts, though new ones are also present. The game was initially released for the Japan-only Family Computer Disk System.

One day, the peaceful kingdom where the mushroom people live was invaded by the clan of the huge turtle Bowser, who possesses powerful magic. Said magic turned the harmless mushroom people into rocks, bricks, and plants, and the Mushroom Kingdom fell into ruin.