what a lot of game makers do is add ads in the game or (less popular) put in game money which they have to buy premium stuff to get an advantage/for lazier people who want normal stuff instantly without actually having to earn it(stick with option 1 if this game doesnt have buy able stuff)+ so the game maker can see and maybe put it back online
i had found the evil grave yard and i took over it, then i found the city hall and took over it and i also have the resources to cure zombieism so now i made the remaining foujrces soldiers and i'm getting ready to try and win in three different ways at once!
maybe you should have occasional/rare disasters that could have a affect on an area like meteor might cause the area to have twice the amount of stone but half the lifetime of people who enter the area and for has long has they remain in the area it would be in effect
i saw the whole place freeze over except for the enemy who had a badass gun and when it unpaused a s**tload of missiles popped out of nowhere! is this an item or is it that the guy was hacking?