The game that got released in the west as SMB2 was a Japanese game called Yume Koujou Doki! Doki! Panic. They basically replaced the four main characters with Mario, Luigi, Toad & Princess. Nintendo felt that the real SMB 2 was too tough a game for the western markets, this later turned up as The Lost Levels in Super Mario Allstars. The western SMB 2 was later released in Japan as Super Mario Bros USA.
Yume Koujou Doki! Doki! Panic
