No, this isn't the 3DS' answer to Super Mario 64. It's nothing like it in fact. We expected a sprawling, open-world adventure, but Super Mario on 3DS is much more like your traditional Mario game - a point-to-point, level-based platformer.
Shigeru Miyamoto's early hint of it being a cross between Super Mario Galaxy and Super Mario Bros. 3 were spot on. The visuals and gameplay are 3D like Super Mario Galaxy, but they're not open. The four levels in the E3 demo were short and incredibly linear - enough to resemble 2D levels at times.
The SMB3 comparisons come in the form of the items we saw and numerous aspects of the levels. The obvious one, as hinted by the game's logo, is the return of Mario's Tanooki Suit - a raccoon-like suit with a tail that, in SMB3, allowed Mario to fly or spin to flick enemies and blocks with his tail. It does all the same stuff in the 3DS game with rather disappointing exception of flight - instead Mario can hover momentarily, extending his jumping distance and making it easier to land on small platforms.
Also from Mario 3 are those bouncy white blocks with the music symbols on them, the random item block that spits out a different power-up depending on when it's hit, mid-world boss fights with one of Bowser's minions (predictably defeated by three stomps to the noggin) and a sleuth of SMB3 music.
But this is rather unlike any previous Mario game in that, while 3D in visual terms, its levels regularly alternate between sections that have you running into the screen and others that have you platforming on a left-to-right side-scrolling basis. The latter still maintain a slight depth - roughly the width of three item blocks, like LittleBigPlanet. So you don't have to jump to avoid obstacles or enemy fire, you can go around them.
The emphasis this new Mario game puts on the 3DS' stereoscopic capability is immediately obvious - the camera often sits at an isometric angle, giving you an idea of the depth of items, while level design often plays on the depth element. There are purple warp blocks that, when hit, transport Mario to another platform usually in the deep distance or up closer to the player (think Wario Land on Virtual Boy). An ink-spitting piranha plant shoots its black tar all over your screen, obscuring your view of Mario (like the Blooper item in Mario Kart).
One level involves leaping along green slabs that build themselves in front of you before quickly disappearing, spearing off in different directions and testing your ability to judge Mario's movements in a 3D space.
We often found ourselves leaping daringly to small platforms suspended over deep, bottomless chasms that feel so much more dangerous with the 3D effect whacked up on full. And the camera also occasionally pans to a top-down view as Mario scuttles along a thin winding path over a lava pool, with fireballs spitting upwards and seeming almost out of the screen.
So there's air of freshness to the action of this new Mario game, not to mention Mario's new roll attack, but unlike Super Mario Galaxy, which throws bonkers new ideas and concepts at you every few seconds, much of what we saw in this was distinctly familiar as long-term Mario fans.
As you can see in the trailer Nintendo released, Mario is stomping Goombas, Koopa Troopas and piranha plants, bouncing along elastic tightropes (Mario Sunshine), dodging Bullet Bills on a floating ship (SMB3), grabbing flowers and lobbing fireballs, butt-stomping wooden poles into the ground (Yoshi's Island/SM64), narrowly avoiding a giant charging spike (Super Mario World), taking on Bower at the end of fiery obstacle courses (SM64) and swimming through 2D-style underwater levels. Pure nostalgic goodness.