wow, I did not even know that these kind of games existed! I really want to try that out… These are great game ideas… This is really an armchair comment, but I suspect they might have great pedagogical (is that a word in English?) value when it comes to co-create universes… One of my greatest fun as a GM was world-building, and I still love doing it, but the problem with that is that it kind of created a “constraint” the imagination of other Players to “fit” with the world of the GM. Well, if course, in a way, that constraint is what the player ask from the GM (to propose a setting inspired by a combination of tropes, etc…). Yet a lot of times this constraint turned out to be “creative castration” for the players in my gaming experiences. They where really frustrating moments, because sometimes players where “destroying” my “ideas” and I was no longer having fun with my “creation”, yet I realised that, well, the games where all about those interactions by the players in the game world… It did not happen all the time, but enough for me to remember them… Of course, everything changed once I discovered games like BW, but I suppose things like Microscope could have improved my gaming perspective when I was playing GM-heavy games like 3.5.