Super Mario Bros.: The Lost Levels, originally known in Japan as Super Mario Bros. 2, is the sequel to the first Super Mario Bros. game on the NES. The game was developed by Nintendo EAD and published by Nintendo. It was initially released for the Famicom Disk System on June 3, 1986, in Japan and did not see a release outside of Japan until Super Mario All-Stars in 1993.
The reason why the game wasn't initially released outside of Japan was because it was deemed too difficult by Nintendo of America, as well as too similar to the original game. The game is different from the original, however, as it uses a slightly modified game engine that includes new levels and other features. The Super Mario All-Stars remake updated the graphics, as well as slightly updated the gameplay (although it was mostly the same).