A simple adjustment
The increase in city growth threshold was not working properly in the last update. fixed.
Though still playing with this number to figure out exactly what the threshold should be.

1. Great People are more expensive, for most eras I set the cost to about 3x the vanilla cost.
Projects also provide about 50% fewer GPP points.
Ancient Era x3
Classicql Era x3
Medieval Era x4 (Greater increase in cost, to play into the harder medieval era theme.
Renaissance Era x3
Industrial Era x3
Modern Era x4
Atomic Era x4
information Era x6
Future Era x10

2. Cultural Border Growth should be slightly slower. The question is if it is too subtle or if it should be a more profound increase. [Increases next plot exponent from 1.3 to 1.5. This should increase the culture cost to acquire all 30 plots around a city.

3. Threshold number for population growth raised from 15 to 20. [It remains to be seen if this is enough to slow city growth enough, without it being frustratingly slow.]

4. Calendar Adjustment: It appears that the rate years and turns pass is not based on what era you are in. Rather there are time windows.: 4000 BC - 2500 BC, 2500 BC - 500 AD, 500 AD - 1350 AD, 1752 AD - 1881 AD, 1971 AD - 2037 AD, 2037 AD - 2050 AD. For each window I can tell the game how many years per turn (in the code it's measured in months) should pass based on game speed. I've tried to make the adjustment based on projections of how long each era will pass for a player, but it is rough and of course games progress is different rates. This will need to be tested more by players playing at various game speeds.

5. Barbarians - A few adjustments here. The base game allowed 3 barbarian outposts to spawn per Major Civ. I changed this to 6. They are still limited on where they can spawn based on city distance and distance to each other. I reduced the distance a barbarian camp can be from another from 7 to 5. I also changed the distance a Barbarian Camp can be from your cities to 3 tiles, instead of 4. Which just makes it easier for more Babarian Outposts to squeeze into the map. There are also various behaviors built in to the game, when you kill barbarians they are less likely to attack your cities, when you lose a scout they become more bold, so for these parts I tweaked the game so that the Barbarians are just a little more bold and less easily discouraged.

6. AI - some minor changes to AI. This will need some playtesting to see if there is a discernable shift. But in theory the AI will be less discouraged from attacking or going to war based on being outgunned. This will hopefullly make adversarial AI players a little more aggressive. Even though the odds may be against them they will be more willing to harass you and throw you off your game. This also helps balance out the fact that HOW the AI calculates whether the odds are in it's favor are flawed in the base game. So it was important to make sure the AI wasn't getting discouraged for no reason.

7a. Civic Costs. Until the new eras are created (which will involve adding a few more civics), we needed to slow down the civics pace. So currently this has been done by raising the cost of some civics. Particularly in the early game. This is not the most elegant solution. And I think that the best way forward is to actually add more civics; however for the time being we are making little adjustments to civics costs to try to keep the civics pace in line with the tech pace.

7b. To further balance for civics, the bonus for a civics from a previous era is reduced, so the cost won't go down as quickly because you progress to a new era. And civics from the next era are much more expensive. I also raised the tech cost for techs in future eras, so beelining into a new era should be harder in general.

8. Changes to Dark Age and Golden Age thresholds.
initial era score to cause a Dark Age is now 18. (so you will need more era points to avoid this)
Initial era score to gain a Golden Age is now 34 (so you need to ear more era points here as well). To balance out these higher costs I added back in a few ways to gain era scores, primarily you once again earn era scores for destroying Barbarian encampments near your village and for earning great people.

9. Religion spreads slower. Again to adjust for the slower game times, religions now spread slower via simple adjacency bonuses. You will need to use missionaries or trade routes.
Trade routes also have changed a little. Now when you send a trade route to another city your traders are much more likely to bring back religious traditions from the cities they visit. SO be careful who you choose to send traders to.