Graveyard Keeper 2

Graveyard Keeper 2 is a satirical medieval graveyard sim from Lazy Bear Games, published by tinyBuild. This time you become the Grand Inquisitor, tasked with restoring a town and defending the kingdom from a zombie outbreak.

You tend a graveyard, gather plants, game and whatever else you can find, build production lines and hand the dull work to your undead workers. Meanwhile you rebuild the town, take on residents' requests, equip and train an undead army and lead it into battle. All of it is wrapped in dark humor and eccentric characters.

Per HowLongToBeat, the story takes about 33 hours and a 100% run about 63. At roughly 2 hours a day (about 60 hours), a month is enough to finish the story and leave time for some optional content. The game is fully single-player, so offline rental access does not get in its way.