At first, keeping your stronghold safe is easy, especially online, but as the game progresses, the amount of enemies sent increases and, inevitably, you will let troops get by you, or they will find another way to reach your stronghold. At which point anything you would have built around the stronghold would be extremely useful. Of course the perfect example of this is a machine gunner, who has unlimited ammo and can be healed by using your wrench (even though he’s, more a person than a building). The enemies, of course, die easily, which makes defending your stronghold a lot easier.

Until they decide to bring in the big guns, A.K.A, the vehicles. Vehicles are the main threat, aside from officers, a player can face and may be frustratingly difficult to destroy without some sort of explosive, which are bought with points that are earned for killing enemy troops and just staying alive. You can  choose to spend your points on the buildings that provide support, on weapons that are vastly more efficient at... killing... than your starter weapons, which are a pistol and a a single-shot rifle that can kill weaker enemies in 1 hit, but leaves you vulnerable after each shot, and you can die quickly when you have 20 enemies surrounding you. You can also spend your points on skills and character boosts, such as extra health, faster respawn, or faster reload times. Those power-ups, which are permanent, can be more useful than any weapon.

It is possible to kill and not be seen, since the A.I isn’t the all-seeing versions that we find in most shooters. It is possible to pass by unseen, as long as you don’t fire a shot, get too close, or stand in a place where you can be easily spotted, such as a roof. Compared to most other FPS titles, the A.I may be a little stupid sometimes, but they are realistic, they will gang up on you, and a lot of stupid can beat a little smart.