That seems to indicate that the game has a vulnerability which can be exploited. That is very different from actively spreading a virus.

And most old games are run within emulators (even something like dosbox) anyway. All you can do is infect that.

But in those days viruses were truly rampant. I have many Amiga disks with viruses on them. As my Amiga had no hard drive and only 1 floppy there wasn't many places for them to go though.

And some legally available contemporary mainstream games are also viruses!

Hello kernel-level anti cheat developers :)