Frostpunk, which casts you as the cold and calculating ruler of the apoclayptic tundra, is free on PC.
Pick up Moonlighter, Frostpunk, This War of Mine and more in the rather generous Humble 11 Bit Studios publisher sale.
Even relatively new games – like Two Point Hospital, Jurassic World Evolution, and Frostpunk – get a discount in the Humble Tycoon sale.