Hahaha, thank you a lot ! :D (I am glad I quitted my previous job hahaha)
It was a blast to discover how to make a fake OS, honestly Godot is pretty well equiped for it ! If you are interested in it, I saw a Godot conf on YT where a guy showcases his fake OS made with Godot, I learned quite a few things with it ! (If you type "Godot conference Holy OS" you should find it)