What I have been thinking would be really cool and fun to try would be to remake zork with llms, speech to text and text to speech.
I think you might be able to do it with a lot of prompting, and having a database that functions like a wiki for the current and past states of the game world.
If you got really fancy, you could also make it a pseudo MMO where the content of the story you create with a character could be used as the basis for a NPC plotline in other people's worlds, possibly reducing the amount of content needed to be written.
If it got popular you could also use it as a research tool, where you could force some subset of the player population have some interaction, and be able to test and get a dataset for counterfactual reasoning.
The next 5 years will be wild.