I'll apologize upfront that this question is so vague.
In the 1980s I was a little kid and my family used to travel back and forth from the USA to London. On a couple of those flights I remember there was a portable game machine that we rented from the airlines. Seems like they were attached to the wall by the galleys and you could pay to rent it from the flight attendant and take it back to your seat for an hour or two. I don't remember which airlines it was, but my Dad said we usually were on Delta or American.
Does anyone remember/know what I'm talking about? I'd love to hear more about them.