Super Smash Brothers - I imagine that they would think that it's either a fangame, a hack, or an elaborate fake picture.

"Who the fuck are Dark Pit, Shulk and Bayonetta?"

Back when Melee was new, you'd get called retarded for suggesting Sonic would ever be in Smash. He was like the Goku of 2003. No one seriously thought he would be a contender.