You didn't have to build on the first floodplain to get the floodplains wheat. Could've gotten the wheat (if the initial scouting discovered it) by moving two squares from the start, founding east of the first floodplains square. Might've been worth it.
I think the Philosophy-Republic gambit might just be a wee bit overpowered.
Good execution of it here, though.
"Fascism Gridlock", heh. It's ironic, and a bit sad, that now that Communism really is quite a powerful government, the AIs always seem to get stuck in Fascism instead. Fascism is basically a slightly boosted Monarchy, in about the same relation that Democracy is over Republic.
You got Sistine Chapel in a flip?! Wow!
Copan 1-Turn Worker Factory: 130BC-1330AD (anyone care to figure out how many turns this is?)
19 + 100 + 16 = 135 turns.
The space research endgame does tend to go slower in C3C. Most of that is due to the weakened Forbidden Palace. With only one list of core cities, it gets pretty hard to keep research at a 4 or even 5 turn pace past the middle of the Industrial Age. If you find yourself running out of cash, setting the cities to the improved Wealth can greatly help; but if you can't research any faster even at 100% science, there's not much you can do. Irrigating to the max and hiring scientists could help (I think RBC1 did that?) but is not worth the management labor. Plus now space needs two more techs, of course. 1720 AD is pretty good for space under all those conditions; I won't be surprised if it holds up as the top score.