The excellent voice acting for the lead characters and the way they are threatening to eliminate that seemingly impassable uncanny valley. Not quite there yet, but Naughty Dog might just be the studio to achieve it. Last of Us 3?
Much like that very lifelike doll in the darkest corner of your green-tinted guest room, the superbly realized characters in Uncharted 4 make you care about them even though their existence is, for now, limited to a game.