I would love a game that helped you learn a language (not necessarily VR though as I don't have that equipment). The game drops you into a world (a country of the language the game is meant to teach you) where no one speaks your language and you have to figure out what people are saying in order to fulfill quests. You get some hints, like maybe you have a simple translation guide in your inventory or sometimes you meet people who can speak a few words of your language. That would motivate me to learn faster than self-taught tutorials.

I'd love to learn French and the game would take place in locations all around modern France.

It would have to a good story. Maybe something in the style of Professor Layton series could be interesting, or something more open world.