I am not sure where to draw the line, but the first electronic home video game I remember seeing was Pong, at my cousin's home. I was a very small kid back then, but I was very envious to my cousin.
I think the first electronic arcade coin op I saw was Space Invaders, which was a magical experience. I was too young to play it, but just watching others play it was enough for me.
But even before Space Invaders, I faintly recall some mechanical arcade games in the local amusement park. I liked one where you were supposed to shoot at helicopters and enemy tanks with your tank, all the objects were actual physical objects behind the glass. And then there was some shark shooting game where the image of the shark was projected to the screen, the image moved around and you tried to hit it with your gun.
Even though they were mechanic games, they already felt pretty much like electronic arcade games, even though normally the only object was to get as many point as possible in the given time, a timer which went to zero. There were no lives, no extra time if you shoot enough enemies etc.
Post edited March 23, 2013 by timppu