I have to agree kulgan, this would be a perfect idea: new play modes. But sorry, this is another subject.
Go and make an own thread (or search the one that's for this).
So, and this is enough of 'correcting' other people, sorry
But I'm astonished (wrong word, isn't it?) nobody answered to my post.
Another random idea: 'sub-ages'. the tech tree is in the 4 ages devided, but they are larger (meaning more techs). and every age has a subage with individual graphics, individual leaders, etc. For example Egypt in the ancient age: In the 'city states' (first subage, no better name came to my mind), King Menes is the leader of Egypt, and when they have researched 90 % of the 'city states-techs', they get new graphics (perhaps?) and a new leader: 'Pharao Cheops', they are now in the ' early kingdoms' subage, after that, they enter the classical AGE and so the subage 'empires', Leader: Ramses (III.?), after this subage, the 'cultural empires' comes.
Perhaps this would be just for the look, but I'm sure that you can include some gameplay things...
what do you think?
mfG mitsho