Dubious Quality

It's not a game when you purchase it--at least, not when it's installed. It's a game generator, and you give it a subject and a genre (and whatever additional detail you want to add), and an LLM creates a game for you. Graphics, sound, rules, everything. 

You could either specify the kind of game you wanted, or you could just hit the "surprise me" button and let the LLM create something for you on its own.

Every single person using this engine would be having a customized gaming experience. No two games would ever be alike. There wouldn't be any guides or sharing tips. You'd on your own for the first time since the 1980s (and even then, you could go on a BBS or Usenet and find tips).

Even better, the LLM would allow you to iterate on what it created. So you could give general feedback, like "too many combat encounters with X type," or you could be extremely specific (in a football game, you could say "offenses run far too often in the last two minutes of a half"), and the LLM would retool the game with the feedback incorporated. 

You might even be able to share the created games. There could be an option to export the game into an installable file package.

I'd play this, and tinker with it, endlessly.