Frostpunk 2

Frostpunk 2 is a city survival strategy game from 11 bit studios. It takes place thirty years after the great blizzard that covered the world: you run a new, now much larger city and must keep it alive while endless winter continues outside.

Here you do more than place buildings. You build districts, research technologies, send expeditions into the Frostland, and decide under what laws society will live. The city council has several factions with opposing views, and every law pleases some and angers others. So each move has to be weighed and every concession chosen.

According to HowLongToBeat, the main campaign takes about 12 hours and a full run about 54. At two hours a day (roughly 60 hours) you can finish the campaign and most likely nearly everything extra. The game is single-player and works offline, so no online connection is needed.