You can get an OpenAI subscription and have it play games right now, today.

A lot of influencers are trying it. You can set it loose on games like Slay the Spire without any training and it can win: https://www.youtube.com/watch?v=9bDG0uuHM2w

That's a general purpose LLM. Actually training a model for a game like that would be old news.

I do have to laugh at how the goalposts keep moving to higher and higher levels like "I need to see it win 20X in a row at the highest difficulty! Why has nobody shown this?"