Super Mario Bros. 2

At the end of World 9-4, the blocks form a word in Japanese. Romanized, this word reads as "Arigatou!", which translates into English as "Thanks!".

In the game's "Lost Levels" version for the SNES game "Super Mario All-Stars" and the game's reappearance in "Super Mario Bros. Deluxe" for the Game Boy Color, the Poison Mushrooms are purple with skulls on them, in clear contrast to the regular mushrooms, which are orange with red spots. In the Japanese version, however, they are brown with black spots, making the two mushrooms look fairly similar.

Nintendo of America followed a strict set of rules during their early years, so as they wouldn't end up like the industry disaster Atari. One of these rules was that they would never "repackage" a game, like Atari had done with many of its titles. Since the Japanese SMB2 was not sufficiently different from the first game, it was never considered for release. An FDS game called "Doki Doki Panic" was rewritten in cartridge form and given a face-lift to be released as the second game in the series to be released on US shores. The concept that the Japanese SMB2 was considered too hard for the American players was a rumor which was started by gaming mags when it was finally released on the compilation cart "Super Mario All-Stars" as a way of boosting sales.