Ask HN: Which platform allows kids to create 3D games collaboratively?

So a few months ago I saw a trailer for a new game-creation platform that allowed real-time collab game making using simple WYSIWYG controls. 0 coding. it showed kids creating not only characters and levels.. but also rules and character powers. did this actually launch? or is it still in the works? *This wasn't Minecraft. It looked more high quality, like Fortnight.