On kingdom attacked by demons, who pulled out of hell. Citadel - this is the last obstacle that does not allow them to move forward. To keep the citadel, you must use the weapon. Root comes with a crossbow, but after the first wave of demons, you will earn so much money that can buy weapons more serious, such as conventional and laser guns, air rifles, machine guns and plasma. When calculating the cost, you must not forget about the purchase of ammunition and repair the citadel.