Overall, RFC essentially builds a new game on top of Civ4. The best part is that there's a number of RFC-derived modmods with varying locales and mechanics. Here's a few that I would highly recommend:
* RFC Dawn of Civilization[0] - An actively developed fork of the original mod that keeps the "vanilla" feel and the global map.
* The Sword of Islam[1] - A Middle East themed variant that although is long-abandoned is one of the most polished modmods
* RFC Europe[2] - Self explanatory. Focused on Europe starting from the rise of the Franks ending with the Industrial Revolution.
[0] https://forums.civfanatics.com/threads/welcome-to-dawn-of-ci...
[1] https://forums.civfanatics.com/threads/the-sword-of-islam-rf...
[2] https://forums.civfanatics.com/threads/rhyes-and-fall-of-eur...
My chief complaint with Civilization games is that they've become a history-themed board game. A fun board game, but less and less it doesn't feel like a history simulator.
The problem with "country" simulator is that countries are a more modern concept, the vast majority of human civilization doesn't feature strong nation concept. How do you model a country that goes from Villanovans to Romans all the way to Italians?
How do you model a civilization which can boom and collapse? How can you set the systems up to support things like the mayan collapse or the bronze age collapse? The fall of the roman empire? Technological regression? How technology truly transforms culture, engineering, politics, etc? Adding +1 to a score is nice and dandy but how you simulate your nation having dynamic classes enjoying luxuries based on location, industry and technology?
I want to see that the urban elite are using silver utensils while the farmers are stuck on wood. I want to see that the civilization used wood too fast and used it all up, causing a collapse.
I actually envision the map as a grid with each grid holding information about the people there. Population, class, technology, industry, culture etc. A rural tile would have low population and be influenced by other tiles. An urban tile might be generating let's say `copper age 3` and in a radius around it for some distance, their tools would be upgrading towards that level. But invading and pillaging this urban tile might lead to those levels dropping, setting a region back in many ways.
The hardest part I have is that I just want a pure simulation with no user input. Gamifying it ruins the purity of my simulation and leads to civilization the game!