I did something similar with my Creative Writing kids at school as well - except we just kind of freestyled and got them to just brainstorm off a blank page... and ended up with a Jurassic-era jungle world where dinos and humanoids coexist...in a human-supremacist society!!
Got some awesome stories out of it, but they struggled a bit with the mapmaking bit. So much respect for you gamemakers who churn out these full sets of rules and gamesheets! Took me an hour just to flesh out the parameters of worldmaking and powerpoint slides for my kids!
If you ever put in any more community copies, I'd love to give this a shot with my students!