I have this, which I’m more or less converting to a research and design platform, and it can be used to crash course a solid first mile in about an hour. I opened it up for free without any progress mechanisms.
I’m going to rebuild it to make it more competitive with something like Duolingo. I have a ton of insight with AI & education now but it’ll take a few months to make it immersive. I think eventually both apps will work together as a first & last mile kinda deal