The poll is pretty inconsistent in asking about ports. I don't see it as that informative to ask about 64 DS but not about All-Stars or the Super Mario Advance line (e-Reader stages included).
For me it's unambiguous: Super Mario refers to the platformer lines, 2D and 3D, ports included. There shouldn't be any argument about these:
- 2D (classic): SMB, SMB2 (JP), SMB2 (USA), SMB3, SMW
- 2D (new): NSMB, NSMB Wii, NSMB2, NSMBU + NSLU
- 3D: 64, Sunshine, Galaxy, Galaxy 2, 3D Land, 3D World, Odyssey
SMB2 USA was completely absorbed into the heritage and identity of the series regardless of its origins, while Lost Levels now looks kind of like the New Super Luigi U of its day. The content added in 64 DS qualifies for the same reason.
I personally count Maker but I can see why not everyone would. More on this below.
The Super Mario Land (not 3D Land, the GB games) series is a spinoff.
The New Super Mario Bros. series is a spinoff.
Yoshi's Island is a spinoff.
Mario Run is a spinoff.
Super Mario Maker is a spinoff.
Agreed on SML, YI, and Mario Run. I think Yoshi's Island is disputable despite its SMW2 branding (and I adore Yoshi's Island), but it plays so distinctly that from the perspective of 1995, when 2D platformers were still plentiful enough that we had no trouble telling series apart, it was clearly its own thing (and to a far greater degree than SMB2 USA).
Maker is an interesting borderline case in that it certainly plays like a premier 2D platforming experience with a lot of mechanics to call its own, all of which are distinctly Mario. I included it, but I can see the argument against it from the perspective of level design, even with the (sloppily) designed event or challenge stages included. We'd be singing a different tune if we really did get a main trunk of Nintendo-designed stages that exploited Maker's mechanics/interactions to provide an out-of-the-box, single-player experience that held its own, with or without the editor.
Absolutely disagree on NSMB, which is as main-line as they come. To say that NSMB isn't a continuation is tantamount to saying Samus Returns isn't a Metroid game or ALBW isn't a 2D Zelda. You don't get to pick and choose based on feelings towards the art style, music, or the repeated design elements across instalments that unify NSMB as a sub-series, which are the typical complaints. It's distinct, it's a revival, and it's unambiguously a straight-up successor to the main-line format. There isn't a case against it.
My conceptualization of a "core" Mario game is a platformer that features a continuous world that is not locked to a single screen and obvious features Mario in a core role. As such, Donkey Kong and Mario Bros, though both platformers featuring Mario, are not really what I'd count as core games despite otherwise being platformers that clearly are antecedents to what I would consider. It'd also thus discount the RPGs, the sports games, Kart, and everything else that is clearly not on those lines. This also does arbitrarily take Super Princess Peach out of the equation, but I also feel like most people wouldn't count that anyway.
I do feel a little bad about leaving the original Donkey Kong and Mario Bros. out of the picture, given their seminal influence in inextricably marking Mario as the icon of the jump mechanic, but I think we can all agree that "Super Mario", as a platforming line, begins with SMB1. You jump, and the screen moves with you: those are the fundamentals. As far as the requirement for Mario to be the featured character—well, there's still a world of separation between, say, Super Princess Peach and New Super Luigi U (even if the latter were wholly stand-alone like SMB2 JP was back in the day).
I realize this makes my own exclusion of SML look arbitrary, but a lot of that may come from the inertia of how they were perceived in the early 1990s when they were current, and portable games were overwhelmingly regarded as inessential spin-off reductions. It was a totally different context from the DS era when the portable hardware line was seen as a viable home for main-line software (in large part because NSMB said so).
The thing about the identity of a series is that sometimes, it's something that emerges retroactively depending on where the series goes. It does in fact matter that SMB2 USA was
afterwards woven into the fabric of main-line Mario, while Yoshi's Island wasn't. It's exceptionally clear now, for instance, that Yoshi is its own branch. We'd probably have no trouble conceiving of 64 as a spin-off if 3D design went nowhere and it was just a one-off experiment before we went back to 2D business as usual. In many respects the 3D games
are a separate series, their status cemented by how it was given the royal treatment as the face of Super Mario at the exclusion of new 2D games. Same story as Zelda. They're too important to regard as anything other than part of the core, but it took a while for them to have much in common with Mario as we knew him, and would look awfully different with a different coat of paint.
Hot take: Captain Toad has a better claim to being a core Mario game than Yoshi's Island.
This is not unreasonable.
Hell, if we want to pick fights over the relative strengths of claims... 3DL/3DW belong here more securely than 64 and certainly more than Sunshine. (And I'm not suggesting there's any question about any of these.)