Nintendo of America wasn´t happy releasing the Famicom Disk version of Super Mario Bros. 2 on the US market due to its high difficulty. NoA knew they needed a sequel, so instead they decided to release the graphically superior Famicom Disk platformer Yume Koojoo: Dokidoki Panic. The original game was quite different to Super Mario Bros. Rather then jump on enemies to beat them, instead you could pick up vegetables or other things (including many of the enemies themselves) and throw them. If you hit an enemy with what you were throwing, it would be defeated.

The four Arabian characters from the original were replaced with Mario, Luigi, Toad, and Princess Toadstool. Each of them had different traits from each other; for instance, Toad could pick up and carry items without any decrease in speed, Luigi had the highest jump, and the princess could float long distances through the air. Unlike Yume Koojoo, you didn´t need to lead each character separately through each stage - rather, you could select a new character at the beginning of every stage.

The storyline was also altered from Yume Koojoo - Wart has imprisoned the Sub-Con, the keepers of the Dream Machine. Mario stumbles across their world through a door that he had seen in a dream, and so decided to help overthrow Wart and restore the land of Sub-Con to its original glory.

Several sprite alterations were included; masks became red shells or Mushroom Blocks, hearts became mushrooms, and so on. Surprisingly, the original already included the POW Block from Mario Bros. so that didn´t need to be changed.

Many of the enemies in this game became staples in the Super Mario series despite their origins in Yume Koojoo, such as Pokey Plants, Shy Guys, and even the mini-boss Birdo. The game also introduced Mario to the free-scrolling world where you could travel in any direction rather than just forward.