Each hero and enemy will have a number, which contains many secrets. When the enemy becomes stronger, new defenders can be automatically unlocked, and they have stronger attributes.
You have to make decisions if you want to be able to defeat all your enemies through various defenses! A good strategy will lead you to victory! Build a defense tower in a designated area, and two of the same level can be merged and upgraded. The rules are relatively simple. If you want to improve the efficiency of customs clearance, you must slowly explore the skills.