Super Mario Bros.: The Lost Levels (スーパーマリオブラザーズ 2, Super Mario Bros. 2) is the second installment of the Mario series, released in 1986 only in Japan and later brought into international market in several remakes and rereleases. It features mostly the same gameplay of its predecessor, but is overall harder. Its numerical place was taken internationally by a different Super Mario Bros. 2.
In the Super Smash Bros. series
While Luigi appeared in previous games, he was just a simple palette swap of Mario. Super Mario Bros.: The Lost Levels was the first game to introduce his trademark physics differences, a higher jump and less agility, which carried over to his appearance in Super Smash Bros..
The track "Super Mario Bros.: The Lost Levels Medley" is one of the default choices in Mushroom Kingdom U. However, despite its title, all the tracks part of the medley originated in the prior Super Mario Bros..