Collapse happened just under 2 years ago.
Survivors, who had been sheltered in underground bunkers, start returning to surface.
Lots of factions - eg. some military factions from mountain bunkers, some civilian factions from private or city bunkers.
Initial focus is about getting food and water and basic protection from the radiation.
Power = supplies of food + water. Run out of power = die.
Each person out of bunker costs some power (their personal food & water supply for surface expedition).
Find way to de-radiate water supply. Research tech to get new building. Then research tech to find power source for that building.
Initial electricity (solar panels or wind farms?) is used for de-radiating water.
Scavenge for food - possibly focus on diet products that are basically just chemicals + vitamins, just add water for a tasty nutritious milkshake!
As local food becomes scarce, need way to travel longer distances without effects of radiation killing them.
Perhaps have junk yard building that acts like vehicle factory? So it's like they're building vehicles from old junk.
People outside initially die of radiation if outside too long. First vehicles are about being able to travel further + protection from rad.
Dog food factories, etc., are found containing large amounts of edible high calorie food. Wars break out amongst scav factions trying to take control of the food stockpiles.
Most tinned food still surprisingly edible due to radiation killing off most bacteria.
Eventually your faction takes control over the stockpiles. Other local factions join you because you have food + water.
Disease breaks out due to growing surface population and germs in some of the food.
Focus turns to medical supplies.