Many players want to experience single-player games cooperatively but lack modding skills. An AI-powered middleware could enable this by observing gameplay and controlling additional characters.
Package as a downloadable tool with pre-trained models for popular games. Include a marketplace for community-shared agent behaviors.
Game studios might license it officially, but indie players would pay for the standalone tool.
Start with support for 2-3 popular open-world games, using computer vision for input.
The biggest risk is performance overhead making games unplayable.