I've played two full games with no game breaking problems, both 6 players. The major problem was that in the first game, we had to resync on turn two and I literally teleported to a different part of the map from my initial start spot, which was disconcerting to say the least, but I went with it. The game sort of ended in a big stalemate at 6 am during the start of the Modern era so I guess it technically didn't finish. The second one played to the Modern era as well with concessions by everyone after World War I resulted in the balance of power shifting to the Celts (my new favorite civ at the moment - until I try the next civ