Super Luigi Bros. has the same plot as Super Mario Bros., except Luigi is the first player. The game has some reversed graphics and all the 8 worlds have been edited as well.
Enjoy!
Super Mario Bros. (Japan, USA).nes
MD5: 8E3630186E35D477231BF8FD50E54CDD
SHA-1: FACEE9C577A5262DBE33AC4930BB0B58C8C037F7
CRC32: D445F698