Limited Resources

What about having a limited amout of resources? When your resources will end you will need to go and conquer other lands. This ideea will boost the war but the market prices will grow. There are also many abandoned cities, we could occupy them and use them as resource, we know that Haypi population is growing , so it won't be a problem to remain whitout resources, this is a war-game and the purpose will be fullfilled. This will also increase the amount costumers, because when you're out of soldiers and resources you will need to buy coins
If you won't do this will be the end of the game, game over for you.
Nobody lives forever

not bad of any idea lol