I mean, how good do you want the games to be? I could probably whip up an "AI Creating Video Games!!!!" in a few hours, it just wouldn't be very good, and it would only be able to create tiny, simplistic games with a very similar scope that mostly rely on a base engine. If you mean like, "Okay ChatGPT, write a Unity video game that's like finite Minecraft but with constant zombie hoards that you have to survive as long as you can," then that'll probably take a lot longer.