The rumor goes like this: Super Mario Brothers 2 was meant to be very similar to SM Bros 1 but a great deal more difficult. Nintendo determined that it was too difficult for the USA market and would not sell well, so they made what we now know as Super Mario Brother 2.
I'm not sure exactly why it is that I didn't like this game but i think it has much to do with the fact that they introduced a bunch of additional aspects to the game that i found unnecessary. I didn't want to pull onions out of the ground.... I wanted to run across the screen and head to the castle that held the princess.
I feel as though there is waaaaay too much going on in this screen. I felt the same about most of the game. It was kind of neat to be able to pick up almost any enemy and throw them in a variety of ways... i guess. There was also what i considered to be quite annoying music going on most of the time especially on any of the underground cave levels - which in Super Mario Bros 1 was just this cool, almost jazz-like song but now it was this tense, almost urgent song that was extremely repetitive and just annoying. I ended up muting my television as a kid.
I suppose the fact that you had the ability to choose multiple characters all of which had different strengths and weaknesses was pretty cool but mostly these additions just added levels of complexity that I would have preferred didn't exist in the game. There is a reason why they ended up scrapping this idea for "3" afterall.
Oh, and those masks that would come to life if you got near them (pictured above) and pursue you for ages, those things sucked. They would even chase you into new levels which I am sure someone thought was a great idea but they just annoyed me.
A lot of people noticed that the game was very different from the first release as I did and years later i would discover that it was actually a direct lift from an already popular Japanese game called "Doki Doki Panic" or "Dream Factory" and Nintendo simply converted this game to suit the USA audience.
I don't know the legal ramifications of all of this but if you care to know it is actually worth looking up on Youtube because you might be surprised that the game you may or may not have fond memories of... Nintendo actually just modified it a bit to insert Mario and other characters. The rest of the game was already created under a totally different theme.