Yume Kōjō: Doki Doki Panic

Yume Koujou Doki Doki Panic (translated as "Dream Factory: Heart-Pounding Panic") is a Japan-only video game developed by Nintendo in cooperation with Fuji Television for the Family Computer Disk System to promote its event called Yume Koujou '87 (translates to Dream Factory '87).

It was later released outside of Japan in an altered format under the name Super Mario Bros. 2, since the original Japanese Super Mario Bros. sequel, Super Mario Bros.: The Lost Levels, was deemed too similar to the original and too difficult for overseas players. Eventually, the altered Mario version of Doki Doki Panic was released in Japan as well, under the title Super Mario USA.

The story starts with two children, the young twins Piki and Poki, peacefully reading a story book. However, they accidentally tear off the last page of the book - little did they know that the book is actually magic! The evil Mamu suddenly appears, and his huge three-fingered hand pulls them into a quirky dream world.

Doki Doki Panic follows a story book structure, and is made out of seven chapters (areas) and twenty pages (levels). Interestingly, although the player can play the Doki Doki Panic with any character, it has to eventually defeat the evil Mamu with all four to finally beat the game (the player can separately save each character's progress).