Sounds awesome! Big fan of the Myst series - Riven is one of my favorite games of all time. There's definitely a lot of appeal to games that have fleshed-out lore where exploring and learning about the fictional world is a joy in its own.
I hope you are able to find the time to get a framework for the game down by the end of the game jam and hopefully work on the project afterwards! The crunch can be hard to manage, but hopefully it can set you up to flesh out this awesome idea for a fictional world afterwards.
Looking forward to seeing what you come up with!