Pong! When I was about 11 there were no game systems generally available but a local electrical store owner built a kit set pong game and poked the controls through the wall of his shop in our small town, the screen was behind the shop glass. I think there was two knobs, one for each player to move the paddles up and down, and a button to restart the game. My brother and I would stand on the footpath and battle each other. Ahh how times have changed
p.s. fuck I'm old