The community has already proven to be very creative when it comes to restrictions. Not only in the early beginnings of Vanilla but also in later days, just remember the 10 Sectors Contest of Doomworld in the late 90's. Keeper of Jericho had another interesting idea, that sets the boundaries of a Doom map to 5 sectors. Who thinks that this is boring might be more wrong than expected as the contest results prove in a very impressive way. But what do I talk, try it yourself.