This game includes resources, buildings, vehicles and also the responsibility of protecting your own city.
The game starts with a character of 0 level, you need to level up to purchase vehicles and buildings.
Buildings differ from small to large constructions and everybuilding has its own provided population.

You need to pay attention to population you obtain via constructing buildings, with this addition you'll be able to build some defence systems to protect your city.
Unless you pay attention to the countdown on clocktower, you'll suddenly face with enemies those only aim is to destroy your city.