Super Mario Bros.: The Lost Levels is a 1986 side-scrolling platform game developed and published by Nintendo as the first sequel to their 1985 bestseller Super Mario Bros. The games are similar in style and gameplay, apart from a steep increase in difficulty. The Lost Levels was first released in Japan for the Famicom Disk System as Super Mario Bros. 2 on June 3, 1986, following the success of its predecessor.
[Source: wikipedia.org]