Thanks for the extra info! Ok yes, it seems like French language was auto-detected. For our internal tests, we added a few lines of French translations to check that our systems allowing multiple languages are working, That's why you can see, for example, "En attendant les joueurs..."
That's really useful to know that the game auto-switched language based on your Windows language settings. We didn't know that would happen!
We don't have the capacity to do full translations at the moment, but for the short-term, I could use Google translate to add all the lines of French UI text. That would, at least, allow you to play the game normally. Sound ok to you? If so, I'll do that later today and then upload a new build and let you know when it's ready.