I think the deduction element is kind of lost because
1: You cant ask custom questions for custom responses, which is kind of the whole fun of the plugin
2: The AI dont actually describe the thief. They just say that they "went that way", but it's not possible to tell what direction they mean, and the best description I could get out of them was "a shady looking guy".
3:The AI dont move or interact with the outer world other than talking to the player, so they can't actually help to find the thief.
I dont want to be overly negative though, because I can still see effort in this game, and that deserves credit. So, I loved the humor element ("Can you help me lose weight"), and the concept is very innotive. Also, the plugin works very fast on this, which makes playing the game more easy and fun. The graphics are also nice! Some things I recommend are:
Let the player say custom stuff to the AI - it's more fun and actually easier to program rather than preset questions.
I guess you manually set each character's description, so you could just put all the AI nodes in an array, pick a random one to be the thief each game, get it's character description and notify all the other AIs with the thief's character description and let them know that that AI is the thief. That way, you get a new thief each time, AI can actually describe them, or at least their personality, and so it re-introduces the deduction element.
Have the AIs move their position in a random direction, that changes from time to time. It'd be super easy to implement but would add lots of life to this game!
I can see that effort went into this, and it's clear that this is neither AI slop nor spam, and thats great, so well done!