Dwarf Fortress is described as 'Single-player fantasy simulator. You can control a dwarven outpost or an adventurer in a randomly generated, persistent world. The world is procedurally generated with distinct civilizations spanning centuries of detailed history, multitude of towns, bodies' and is a popular city building game in the games category. There are more than 25 games similar to Dwarf Fortress for a variety of platforms, including Windows, Steam, Mac, Linux and Wine apps. The best Dwarf Fortress alternative is RimWorld. It's not free, so if you're looking for a free alternative, you could try Veloren or eSoclife. Other Dwarf Fortress like games are Gnomoria, Stonehearth, Oxygen Not Included and Banished.
Nowhere near as difficult of a learning curve, but has a lot of the same mechanics, with added futuristic sci-fi events. Can micromanage and prioritize down to a tee, main gripe with it is there's UP/DOWN to the world, so you can't build towers or bases deep underground