Nintendo confirmed some of its roster today during E3 for the new Smash, re-iterating that every fighter in the history of the series is here:
Mario, Samus, Kirby, Bowser, Link (with Breath of the Wild powers), Donkey Kong, Fox, Falco, Marth, Zelda, Sheik, Villager, Mewtwo, Meta Knight, Sonic, Peach, Pikachu, Ice Climbers, Inklings, Captain Falcon, Wii Fit Trainer, Zero Suit Samus, Pokemon Trainer, Ness, Lucas, Ryu, Ganondorf, Ike, Cloud, Snake, Jigglypuff, Pichu, Diddy Kong, Olimar, Lucario, Robin, Lucina, Bayonetta, Game & Watch, Grenjinja, ROB, Dr. Mario, Pit, Dark Pit, Palutena, Corrin, Bowser Jr., Toon Link, Young Link, King Dedede, Rosalina & Luma, the three Miis, Wario, Little Mac, Pac-Man, Shulk, Wolf, and Mega Man.
That’s a mouthful! More is rapidly on the way!
Source: Destructoid Ice Climbers are back in Super Smash Bros. baby! And so is Snake! And every fighter in Smash history