Rapture
Rapture is upon us and only the worthy will survive. The knights of the dead are moving through the people of this world taking those who are unworthy to deaths embrace. The problem for death is that these horsemen are spread a bit too thin. And judging who is worthy takes a long time. Some smart people have figured out a way to beat the system so to speak. They have set up soul factory towns to keep the knights occupied. These soul factories have to have a population growth higher than what the knights can consume.
In Rapture you oversee a soul factory. Your job is to manage people and allocate resources in order to generate a large enough population growth to feed the needs of the keeper. People will procreate when they are happy and well looked after. Eventually more and more keepers will appear outside your soul farm which require more and more people to feed them.