I get it, anyone claiming "first video game" is going to start a bar brawl.

But pedantry aside, the also rans, even if they were previously rans, are not interesting. They did not spawn million-dollar companies, change the course of entertainment around the world.

Having huffed though, were I the author I would have anticipated these responses and probably gone with "first wildly successful commercial video game".

Christopher Strachey wrote a version of draughts/checkers for the Manchester Mark 1 that was fully functional in 1952. This is IMO the first video game. Earlier candidates use single-purpose display hardware, which disqualifies them from being "video".

https://en.wikipedia.org/wiki/Christopher_Strachey

There was also SpaceWar! from MIT, which Nolan Bushnell turned into a standalone cabinet game. Though I think you could make a case for Pong being the first coin-op video game, a commercial game rather than something that primarily existed in academic labs.