First let me say what you're doing is incredible, I'm so glad somebody coded something like this! The issue I encounter is that after a while the chat gets stuck. It will repeat at every message everything that was written before adding only a small percentage of new content. This halts the story and conversation and doesn't get unstuck. You really have to close the chat and create a new one from scratch, losing all the progress in the story. Fixing this would be of great help in keeping it interesting and immersive, I'm really enjoying this service.