I like the game. I am waiting for five more hours until I have enough stone to start a new city. One thing that I would like to see in the game is in the battle message I would like it to let you know how much resources you won from the battle. That is my only suggestion.
On another note I noticed that when I drag my mouse across the screen it isn't very fluid and responsive. It is kind of sticky but this may be my computer.
I also think that you should save snapshots of the world so that people can go through and see how it changed over time.