I've fiddled for a long time on a campaign that in my head I title "Tales around the Embers". Basically, the Goddess of Wyrd, Destiny and Time has died, and time has pored out of the world. Mortal magics have found ways to generate some, but it takes constant rituals. Three towns/small cities that were the settlements on where three pre-Loss borders came together, have banded together. In the generations since they have grown into one large city enclosing croplands and grazing lands, and rituals keep time within. Births seem to help to fill the area with time. The city knows it needs to stay together, but that doesn't mean that the old racial tensions are gone. Each settlement had it's own factions before, and now it's a mess of intrigue.
In the most recent generation they have found ways to create portable time lanterns, which can allow small groups to leave the confines for days, even weeks at a time, though they must return. Metal wearing out and other lack of resources forces expeditions, but elsewhere in the world time ran down and then froze.
PCs can come across bandits sitting in ambush from before the Loss, battles in the midst of being fought, explore castles frozen in time until they come and awaken them. I had planned that they would find that there was a war being launched between two of the countries, and choices to rescue these countrymen from being refrozen without time or to bring them back, with their fresh tension and more mouths to feed.
I had planned on it being a mix of exploration in the timeless and intrigue, diplomacy, and factions in the city. Depending on the players I could see major campaign goals being unifying the city or trying to find out what happened to the goddess of time and getting her portfolio filled, if they wanted more gritty, diplomatic, or epic storylines.
EDIT: One of the lines I wanted to play with is that there is all this prophesy around, and it didn't point to the PCs. But it was all now meaningless because Wyrd & Destiny were as shattered as time. Eveyone was free to make their own destiny, and as such even the gods trembled, unsure of the future and even if they will be replaced. This wasn't to be an obvious thread, but an underlying one about the PCs are as heroic as they want to be, and why the gods have become so distant.