Pros:

-Great Atmosphere and Environments
-Great Events and Content
-Zero Bugs and Errors
-Good Pacing

Cons:

Too Cooridoory
Poor machinegun placement and 

Conclusion:

Great campaign, me and my friends had a blast playing it. The con I mentioned is because the hordes were never a threat... you could always just back up into a corridor in most places and funnel them into a line for easy multi-kills/spray.

The machineguns were never pointed in the direction the hordes were coming from for events except for the first one. 

Other than that absolutely brilliant game, the ending was boss, the wicked colors made it semi challenging to see things that weren't lit up.