Midnight is the end of a civilization that fails itself.
But what comes after?
When pollution weakens temporarily, survivors emerge from bunkers. They salvage the remains of a broken world and prepare their utopia. Until the clock ticks again.
Access the surface only for a limited time to gather resources for your utopia. Beware of animals and the BLOO rising from blood-soaked ground.
Civilization is rubble. Remaining resources, industry, and machines wait to be discovered in a procedurally generated world. And fought over.
Issue orders across the map to the living and machines. Or directly micromanage critical skirmishes. Mighty heroes will emerge too.
Explore a shifting tech tree. Perhaps a little bioweapon, propaganda, or other horrors can help establish your "utopia"?