...or DID they?!?
(did they? I wouldn't know.)
Oh, Mario Maker. I've only watched clips of it.
It should also be noted that back when I was in my SNES youth I bought countless issues of Nintendo Power and other things that had maps and shit in them to help you find stuff like hidden exits so I probably had some, uh, help there.
When I was 8, going through all of SMB3 to "conquer" it (LOL, now you're playing with power!!!) would have seemed pretty damn Herculean...of course, Mario All Stars save-by-world feature destroyed that. I've never sat down and played it all the way through in one sitting which would take...uh, I dunno, six, seven straight hours of staring at a screen? Now we know why the warp whistles are there!!! (Would ANYONE have thought to squat on that white block in the third level if it weren't for guides and stuff? Who would have found that by themselves?)
I'm trying to think what the hardest SMB3 levels are....hmmm, World 7-7 would have been pretty freaky the first time through?!? How about the World 8 fortress where the real exit is hidden at the very very very far end. Bowser's Castle still isn't too hard but I bet a lot of people got blasted by the laser statues at the beginning.