Sure! Here is a playable sample game that meets your requirements:
This game consists of a chatbox div where messages will be displayed. Each character has their own interval to send a chat message. The game starts automatically when the page is loaded. The chat messages are displayed in the chatbox div, with each message having a specific interval set for it.
Note: In a browser, you wouldn't see natural language processing in action as you would in a normal conversation. Therefore, I've simulated the chat messages using hardcoded strings.