Apparently the ever-popular Super Mario Bros 2 game isn't quite what it appears to be - at all. In fact, the entire world itself was lifted from a totally different game called Doki Doki Panic, with a few key adjustments.
The original game wasn't even a side-scroller. Instead, Doki Doki Panic unfolded vertically, following two players as the hopped endlessly upward, hurling bad guys around rather than stomping them in the Mario style.
In order to flip Doki Doki Panic into a version of Super Mario that fans would love, all of the characters had to be swapped out in favor of Mario, Peach, and, of course, Luigi. The real question, though, is why didn't Nintendo just create a new game themselves? The slightly confusing answer: they did.
Check out this video and learn about what really happened during the making of Super Mario Bros 2.