This is the Famicom Disk System game which Nintendo of America used to make their own version of Super Mario Bros 2, because they dident think that the Japanese version, which just starts off where SMB left, would sell in the US.
Doki Doki Panic (aka Dream Shop) was already a huge success in Asia, sold better than their version of Super Mario Bros 2, so it would be a 100% success in the US for Nintendo. But the US gamers thought that Super Mario Bros 2 was too different from the first Super Mario Bros game, though the
game did become a huge success.
Nintendo of Japan also released this new version of Doki Doki Panic in Asia, which now starred Mario, Luigi, Toad and the Princess instead of "Mama" and the three other original characters. Nintendo of Japan named the game "Super Mario USA".
Its a shame that this great game was reprogrammed into Mario Bros 2, but I guess every other videogame character had a very unsafe life back then, because Nintendo wanted Mario to be their
success character.
I wonder if the Doki Doki Panic would have been just as popular as Mario today if the games of star wars galaxy of heroes hack was released all over the world. But are the game completely the same in both versions?, you migth think. Yes! Nintendo dident have to do a lot of reprogramming. They changed the 4 player characters, ofcourse, and a few other things such as the "warp door" between the levels which in SMB2 is an Eagle while in DokiDoki it's a African mask, the subroom bottle in SMB2 is an Aladdin lamp in DokiDoki.
The Doki Doki Panic Ending is very short, it stops in the room right after defeating Wart (see 4th pic
on the left of the screen), while in SMB2 it shows all the characters in the game, a player characters "score" (no of levels they have completed) and finally Mario lying in his bed dreaming. Almost nonone I have talked to knew that Super Maio Bros 2 actually was a Japanese Famicom Disk game
called Doki Doki Panic, or as some people would prefer to call it.. Dream Shop.
It might be impossible to find a working Doki Doki Panic Disk today, Famicom Disks are/were very
bad and most of them might be destroyed by now, but pirates in Asia has converted the game, so that
it now is available as a Cartridge game. (I will hopefully get my copy from Asia soon!).
So if you want to play the original, I suggest that you contact someone in Asia, a store or something, and get a copy....