I'd travel back to 1990, when me and my dad are playing the original Legend of Zelda together, loving the exploration and freedom, and showing them/me the Breath of the Wild, which is easily doable being played on the portable Switch. They'd get to see a game that is so large, the original NES games map takes up just the tiniest fraction in comparison and that I could spend dozens of hours just getting lost in that world. Instant mind explosion.
(http://www.reactiongifs.com/r/2013/10/tim-and-eric-mind-blown.gif)