More colonies? That means more people! More people means more conflicts! More conflicts means more war, too. And if I've learned one thing from playing too many PC games over the years, it is this:
*Adopts a really awesome look, leaning against a wall and looking cold and distant momentarily.*
War... War never changes...That, and that more places to go means usually, more entertainment! Woohoo!
Also, a suggestion if I may. If you want to add some danger to a huge city, without making it like the Snake Lake Waterfront (I mean, constant danger) you could make a random chance every turn or move, that thugs and such would leap out and attack you. The chance would be really low, I imagine, enough for the occasional attack without it being redundant.
For real style, have the attacker(s) get first strike. That'll really keep the player on their toes. Maybe a chance of a randomly generated character being attacked, and the option of having the player save them (or not!) for a reward?
Just random thoughts. Anyways, awesome work!

I have to try it, but I still have to finish GearHead 1!