Been working on something similar as well!:
All conversations are currently being powered by GPT3, and I’m using Unity + Google text-to-speech to bring them in the game.
Wrote some of my thoughts of where NPC systems could go, I think GPT3 (and other transformers like it) could power good chunks of that vision:
Biggest problems I’m currently thinking about is cost (I’d love if there were some flat rate or mega bulk discount), how to cement things GPT3 says into the game world (maybe codex can help with this), and game engine code.