I was wondering if there could be kinda kampaign style game with no cities only solders battling (possibly workers for support). And there would be no builfing just fighting. There are some interesting possible variations:
Allow leaders to capture enemy solders (I though to allow anyone to capture anyone, hoping that you would first need to win a battle, but it does not work like that, you simply capture unit and thats it), of course leaders death means you loose game.
Have huts and setup it in a way that you could only get units from them, thus you could enlarge your forces by finding huts
Also have workers for base creation, I think this is a must.
Have huts, make huts always transform into cities, no setler units in game, you can only find city from hut or conquer it.
I think by editing ruleset it is quite possible to make starting units represend whatever you want, i.e. start with planes paratroopers, spies and stuff, though there are some limitations, but the point is that it is not necesarrily stone age battles only, though even that could be interesting.
Some other observations:if game is totaly cityless map should be quite small, and most likely should have leaders for easier quicker end. If game has cities from huts map can be quite large and hut density should be adjusted to our preferences.
One last important thing - huts are a bit limited, it seems you can not change much from the ruleset, so always get units or always get cities might require source modification, though considering that we had game with 3 leaders and it also required source modification it shouldn't be too problematic as changes shouldn't be difficult, also changes would be server only as with leaders.
EDIT: my mistake, hut behavior is controlable in rulesets lua script file, so there is no need for code modifications!
I would also guess that such games would be much shorter (if completely cityless) and might be nice/interesting to have in between long games.