Oh My Git! An open source game about learning Git

That's pretty neat. Fun is a great way to learn new things.

Can recommend. Learned something from it, even with multiple years of Git experience under my belt. We've been handing it out to people new in our team for the past two years, and I feel like it helped quite a bit.
It can be worked through in about 4–8 hours, I'd say, obviously depending on your previous experience.

Any alternate method to get the game? Itch.io downloads don't work on a slow connection like mine.