This is a very.....unique game.  It has a short campaign that has you going from one point to another to another to another and to another.  it has 3 chapters and 5 missions per chapter clocking in at about 3-5 hours to complete it with 3 levels of difficulty: normal hard and inferno.  there are over 300 guns that are split up into seven common types of guns: assault rifles, rocket launchers, missile launchers, grenade launchers, shotguns and sniper rifles.  Even though there are alot of guns theyre practically the same.  the armor classes are ok but nothing special with there being battle which has the most hit points and most destructive and powerful guns and can use a shield which completely eflects attacks but seriously slows you down.  Flight which uses energy based ammo thats basically like using the trooper.  A energy meter is used for flight and reloading which is a serious pain since you will want to fly and reload which will cause the meter max out and wait till it completely refills so you cant reload or fly.  tactical is the same as trooper except it can place turrets and cant use shotguns.  The trooper is just a grunt where he can use every type of gun whether weak but rapid or powerful but slow and has no special abilities.  The survival mode is probably the worst since you cant use different classes or your character from the campaign.  Your only a trooper with default guns to choose from and nearly everybody i have played with goes for the rocket launchers so it makes it way too easy.  the waves arent made well between each where you could be fighting 3 large robots one wave which can be difficult and the next wave just a bunch of spiders making to be a very easy wave.  not to mention it gets very dull when your just locking onto enemies and firing with no skill.  and even with all these problems this THE most fun game ever made.  It has great controls and with a full group on campaign its like your an actual team needing to save earth from the ravagers.  Shooting hordes of large bugs with generic guns has never been so satisfying since 2017.  With all the large robots and spawners needed to be destroyed with mindless shooting it brings so much joy to watch them fall then blow up.  This is like an arcade game like no other that should be remembered for the rest of time.  not to mention it has great online connections so its like most co-op games where your sitting for like 10 miinutes to find someone to play with, its very fast with some of the networking i have seen in awhile.  This game is a once in a lifetime gem that should not be passed.