Frostpunk

Frostpunk is a “society survival” game from the Polish studio 11 bit studios. A blizzard has frozen the world and you lead the last city on Earth: your decisions determine whether people live to see warmth again. You have to manage both the citizens and the infrastructure — right up to the breaking point.

It is a city-building strategy: around a huge heat generator you place houses, workshops and mines, gather resources and research new technology. The key thing is not only coal and steel but laws as well: every decision you pass shifts the hope and discontent of your people, and you often have to choose the lesser of two evils. Since release the game has gained Endless Mode, the “Fall of Winterhome” scenario and a photo mode.

According to HowLongToBeat, the main story takes about 11 hours and a 100% run about 56, so in a month at roughly 60 hours you can finish everything, with almost no room to spare. The game is single-player and works offline.