That's very unusual! What was your motivation for creating an o/s simulator?
If you like this kind of challenge, Pico8 seems interesting (it use Lua language, and they have special offer for schools, that could interest your school for the price) https://www.lexaloffle.com/pico-8.php?page=schools and to try some little pico 8 games https://www.lexaloffle.com/pico-8.php . one last questions did you use GB studio? And is it easy to learn?