Super Mario Bros. 2/Yume Kōjō: Doki Doki Panic

Yume Kōjō: Doki Doki Panic (lit. "Dream Factory: Heart-Pounding Panic") is a 1987 platform game released for the Famicom Disk System exclusively in Japan. It is about a family who plans to rescue two children. "Doki doki" is a Japanese onomatopoeia for a rapidly beating heart, and it is commonly found in Japanese video game titles, carrying connotations of excitement and anxiety. The game is best known for its Western conversion in 1988 as Super Mario Bros. 2, a Nintendo Entertainment System title featuring a cast of Mario characters. It was not until 1992 that this version would be released in Japan, albeit titled Super Mario USA.

Game cover
Title screen

Yume Kōjō: Doki Doki Panic was developed in cooperation with Fuji Television to promote its Yume Kōjō '87 (tr. Dream Factory '87) event, which showcased several of Fuji TV's latest TV shows and other products at the time. The game featured the mascots of the Yume Kōjō festival — a family consisting of siblings Imajin and Lina and their parents, Papa and Mama — as its main characters. The rest of the characters, including the main villain, Mamu (named Wart in the Super Mario Bros. 2 release), were all creations by Nintendo for the game. The game takes place within a book with an Arabian setting. All four characters are playable, and the game is not fully completed until the player plays through as all four.

Even though it was not originally conceived as a Mario game, Shigeru Miyamoto had a larger involvement in this game than he did with the original Super Mario Bros. 2 (known outside Japan as Super Mario Bros.: The Lost Levels) which was released in Japan. Some elements from the Mario universe already existed in Doki Doki Panic, such as the Starman, Coin, jumping sound effects, the POW Blocks, and level warping. The game's soundtrack was already composed by Kōji Kondō, the composer for the first Super Mario Bros. game.

For Super Mario Bros. 2, the Yume Kōjō family members were replaced with Mario, Luigi, Princess Toadstool, and Toad, and the Arabian elements were removed. Numerous other small changes were made, such as the B Button on the NES controller making the characters run. A full list of differences can be found on the Changes page. Several elements in Yume Kōjō: Doki Doki Panic would later become staples of the Mario franchise, such as the characters Birdo and Shy Guy.