Legend of Zelda: Legacy
First and foremost, everybody talks. Including Link.
In the process of saving the world from an evil beyond even Ganondorf, he uses the Ocarina of Time to borrow equipment, skills and magic from the past, in addition to new stuff.
In the end, Zelda unites the power of the sages with the magic of the Ocarina to fire an arrow of Triforce-enhanced light energy from multiple points in time, followed by Link plunging the Master Sword into the ultimate evil's soul. Ganondorf admits that his long life has given him wisdom, and he's the one who wishes for the power of the Triforce to set the world in a state of balance for the rest of time.
Oh, and maybe it's set in a kinda steampunk-ish era, because everything's better with the steampunk motif. No, really, just because they're all set in this ye olde English fantasy-type setting that doesn't mean the whole shtick couldn't work in other time periods.
Annnnnd maybe it's episodic, just to REALLY piss off the fans.
Super Mario... something
Hrm... 3D or 2.5D? Why not both? Play it retro, then switch modes and get a whole new experience. Or maybe mix the two together somehow. I think one of the Paper Mario games did that alright.
No talking except for Peach shouting MARIOOO. Everyone else talks that usual gibberish like the Mario&Luigi RPG games. And Luigi figures into the story, and like Mario 2, he can jump higher than Mario.
Plot: Let Square-Enix handle it, because "Bowser kidnaps Peach" just doesn't cut it for the definitive end to Mario's adventures. But psych out the fans by making it LOOK like that's all that's happening. Bowser kidnaps Peach, you run after them. After a few short introductory levels, the very first castle has Bowser. Turns out he needed Peach so he could talk to Mario about the big evil. Notice a pattern here?
Mechanics: Make a Mario RPG, then throw out (most of) the RPG elements and make it a platformer, with a couple action/adventure mechanics thrown in for good measure. Mario's got a hell of an arm, why not make him punch stuff a few times? Grab a hammer, beat the stuffing out of everything. Bonk a koopa, then use the hammer to send it careening down a hallway, knocking out everything it hits. The sky's the limit.
Metroid: Genesis
Remember Metroid Prime? The creature itself, not just the games. Turns out there are more of them! And a grand matriarch of the whole Metroid race. Anyway, like Metroid 2 (which damn near nobody played) there are different breeds of Metroid in various stages of growth, starting from the floating head-crabs we've come to know and love, and it goes all the way to towering monstrosities designed by H.R. Giger. Oh, and Ridley appears, because he has to.
Mechanics: Full-fledged gunship battles. No compromise. The whole thing is in 3D, but with the press of a button you zoom into "scope" mode to snipe stuff in 1st-person, a la Metroid Prime. OOH, if it's on the Wii U, you can use some of the controls for movement and stuff like normal, but have a button or two and the controller-screen thing for precision aiming and scanning.