On another note, I really hate the Japanese Super Mario 2 freaks that perpetuate the "American Super Mario 2 isn't the true sequel" nonsense. I blame the oft repeated, never confirmed rumors that they changed the game because American's are stupid and need easier video games. No. These fans only played the polished SNES Lost Levels version, not the glitch filled, impossible, crappy Famicom Disk version. Now, I never really liked the first Mario game. The jump physics were off, the random maze castle levels were gratuitous rather than challenging (not counting Koopa's final castle which is actually kinda fun), and while respectable at the time, it's retrospectively not as ambitious or fun as, say SMB 3.
All I can say is that the Japanese SMB 2 comes off as an abusive fan Rom hack with nothing outside of sheer masochistic challenge that's appealing. Is American SMB 2 a little too easy? Yeah. But is it fun? Frag yeah. And the unique characters were retconned into the series as early as the very next installment. So yeah, culturally, American SMB 2 is the true sequel, it's the creator's true vision as Doki Doki Panic was supposed to be a Mario game at some point.
Plus, if Mario detractors feel the franchise's biggest sin is repetitiveness, Japanese SMB 2 doesn't exactly help against that case.