The Retro Duo Portable Game System is pretty much the dream configuration for any retro gamer. Not only can you play solo, but it also hooks up to full-sized televisions as well. It also comes with two extension controllers enabling tag-team, two-player gaming. In addition, the extension controllers work with the embedded screen on the main unit or the TV-out display. This means that you can play Super Mario Kart head-to-head in the backseat or in the basement on the big screen.