I embedded it at a game studio for PC and game consoles a few years ago. We opted for JavaScript over Lua for reasons I can’t disclose, but runtime performance was sufficient for our needs. I liked having reference counting since the determinism gave our tech lead a bit of confidence before cert.

We had some performance issues with marshalling and unmarshalling, but that was mostly due to API design and how our codebase was structured. As per usual, optimizing scripts was the best bang for buck.