It seems the world’s first device closest to a video game was basically a “Cathode-Ray Tube Amusement Device” developed by Thomas Goldsmith and Estle Ray Mann. This device used “eight vacuum tubes to make a tiny glowing speck of light appear to fire, missile-like, at tiny line-like targets…”. And how exactly did the players control the objects? Using knobs !! A patent was applied in 1947 for this device.

Only after a decade did “Tennis for Two” show up which was based on the same principal as above, only a little better. “Tennis for Two” was officially termed as a “video game” and therefore considered by many as the first of its kind.

[source: pcworld.com]