I can 1-up 1956
In 1951, the release of what I would term the frst video game was shown off. It was called Nim, and played very similar to tennis viewed from the side of the court. The display more resembled the Cathode Rays Tubes seen in science labs than in (CRT) monitors that we now know
http://www.goodeveca.net/nimrod/
A year later (1952), someone released A game of naughts and crosses called OXO exclusively for the EDSAC
http://www.pong-story.com/1952.htm







