Having played a game from when the Celts start to the end, I've noticed a lack of civs rising again. I think only Greece rose again around the modern period, and the Incas towards the very end, with <20 turns left. While I think that the 2nd chance collapse is good, maybe for some civs that historically did collapse, particularily the ancient ones, it could be returned to normal collapse?
In terms of the game itself, it was interesting enough, with Britain winning a time victory fairly comfortably, with Russia second. The HRE survived to the end, being powerful in the Middle Ages as an Islamic power before being vassalised by Spain and forced to become Christian, then became Britains vassal. Both Persia and the HRE held Incan cities until the near the end when the Incas respawned. France was powerful for a period, before becoming Soviet and collapsing and never returning. Britain vassalised Holland, HRE, Persia, India, Zulu by the end of the game. Germany never got going and was eventually destroyed by Russia. Egypt was powerful for most of the game before collapsing. The US started slowly, but eventually vassalised the Native Americans who lasted until the end and occupied a few Aztec cities. The US finished 3rd in score at war with China who was 4th and had a Khmer vassal. Spain was 5th I think. The Aztecs didn't last long at all, and don't remember seeing the Mayans. Korea lasted until near the end before being taken over by China. Japan was a mid-power Russian vassal. Turkey controlled the Anatolia, shared the mid-east with British Persia after a war and several African cities, and vassalised Arabia, and Egypt until Egypts collapse. Mali was a mid-power, being a British vassal before freeing itself. By the looks of things Ethopia lasted a few centuries before collapsing and Egypt moved in.
Sumeria collapsed early and Babylon was taken out by Persia.
The Western European powers were Christian, Russia Islamic, Egypt & Arabia Islamic and Turkey Jewish.
I played as the Celts, holding only Ireland, Iceland, Greenland and a South American city by the end, and being near the bottom of the score-board throughout
Like other poster have said, it would be great if you could merge this with some of Dawn of Civs features.