As for what 2018's big game is, could be many things. Nintendo is playing their cards VERY close to the chest. I mean shoot, they managed to keep Pokken DX, Metroid Samus Returns, AND Metroid Prime 4 secret until the announcements PLUS they kept smaller projects secret too. Animal Crossing, Pikmin 4, Pokemon all strike me as strong possibilities. Metroid, unlikely. They could have Fire Emblem in the fall, go for more of a tag-team approach of two middling level killer apps (Pikmin and Fire Emblem for example) instead of one huge one. Or they could surprise us completely with another announcement, who knows.