Yup! One of the first programs I wrote for Buttplug was the Game Vibration Router. It hijacks force feedback signals from games using DLL injection and reroutes them to hardware:

https://www.youtube.com/watch?v=W6qbNcgl2fI

I also built Twine (interactive fiction engine) bindings because our tutorial needed to be branching:

https://github.com/buttplugio/buttplug-twine

We're working with a couple of different game studios on Unity integration, that's just taking a while because I'm having to rework our C# codebase a bit first.