https://store.steampowered.com/app/646500/Egypt_Old_Kingdom/(copy/paste of the Steam description for those who don't want to click the link right away. And I'm sure it can describe better than I can.)
Before the description. It released a free DLC today (Master of History). Before, it was limited to 300 turns. But the developer(s?) introduced endless mode. They also added mummy invasion mode and alien invasion mode as bonuses, so not entirely historical for those two but more for "fun". The dev(s?) added a lot of content though for a free DLC
With that, its also on sale till September 17th 2018. 40% off, so its pretty cheap now.
Now for the copy/paste of steam page...
You are one of the multitudes of incarnations of the great Horus, and side by side with the pharaohs, you are fighting against the mighty Seth, who unleashes numerous disasters upon the lands of Ancient Egypt. Win wars and overcome crises, discover new technologies, worship your gods and conquer neighboring tribes! Are you wise enough to help the ancient kings to unify Lower and Upper Egypt, build a stable economy and to erect the Great Pyramids?
Based on real historyYou will find yourself in Memphis, 3500-2140 years B.C., the time of the first six dynasties of pharaohs. You will unify the country and create a prosperous kingdom, which later will have to face the havoc of the First Intermediate Period.
Construction of the Great PyramidsYou will lead the construction of pyramids, choose their design and materials. This process requires tremendous investments, but it is the only way to keep peace and order in the country.
Ancient society simulatorYou will not only deal with the problems of farmers and craftsmen but also make important political decisions, which will define the future of the kingdom. Numerous challenges and events of different scale await you.
Ancient mapsDiscover the world of the Old Kingdom: exploit new lands, send expeditions to different places, and meet different cultures. Use every opportunity to learn about your surroundings and to expand Egypt's borders.