Pros:

- really good setting.
- zombies, zombies, zombies...
- easy to navigate
- carefully detailed
- ammunition lying around is must-use to make your life easier.
- the first level is epic. I got more melee kills than anywhere in L4D2.

Cons:

- LIGHTING. (fix it. It is almost always unnatural. Except, sometimes, for windows.)
- no history at all.(create one.just do it.please.and change levels accordingly.)
- copy-paste with no justification.
- more different weapons, please.
- more free space (it might be just my preference, but I want to hold a bigger final zombie rush; right now it is to easy to shoot even the big number that is there).
- music and sounds. A zombie rush should sound like a zombie rush (heavy metal with a lot of base would be proper, I guess). A Smoker fulfilling an Hunter-Killer role should sound accordingly.

Conclusion:

Seriously good idea, seriously good intention to make it perfect, seriously thorough work needed to polish it.
And LIGHTING, LIGHTING, LIGHTING...
Too much light from small light sources, absolutely not enough from a bright sky.

Anyway, it is a very good campaign to play co-op!