Pros:

Different Areas
Med Kits are not overly plentiful
Fun, Logical progression

Cons:

The final scene is insane. As if the over abundance of tanks were not enough, you also have to cope with too many hordes. You can't move. 

Finding the defensible position was not hard but once the rescue shows up you can't see it.  

Conclusion:

If you like playing a fairly long campaign, but don't mind not being able to finish then this is for you. I had fun up until the end, then it felt like I wasted my time.

Pros:

Campaign was fun
Ammo seem to flow, never ran out

Cons:

No sky loaded
Too easy for hardcore players

Conclusion:

Overall it was worth the download time. Was an enjoyable play.