Pros:

Great idea
Really looks like Dawns Of The Dead
Nice map editing
Not too long not to short

Cons:

The last two maps were horrible
To many tanks/hunters/spitters

Conclusion:

It is a great concept and I LOVE the idea. The first maps where cool. Except for the last two, they were f*cked up. There is no way to do this in expert, I tried the first time and I died died and died. It had to be done in easy wich is a pitty. Its to many hordes wich makes it to crowded, wich made it lliterally IMPOSSIBLE to get trough the ventilation tubes and other small area`s. Also there we to many tanks, it was easy to kill because I had to play in easy but it sort of got on my nerves. But overall you did a hell of a job! 

Pros:

-Great idea
-Great enviroment
- Nice idea with the voice acting
-

Cons:

-Why dindt the dam blow? 
-9/10 times I could not hear the voice because there was a horde...
-Final was easy, but long.

Conclusion:

Sorry, I thought a bit more of this map. The idea was great, though I had the idea that from the beginning the plan was to blow up the dam... because we needed to heat up the pipes and all. But at the end it dindt blow.. that was a pitty.
The idea was amazing, and the maps looked great aswell. Keep up the good work!

Pros:

- Amazing concept.
-Amazing...fire tornado?
-Very cool idea to put l4d1 survivors to help out.
-Epic Final
-Great disaster

Cons:

- Lag lag lag, but I understand why.
- To crowded, it started to get annoying
- Kind of unclear where to go ( in the building where you have to run and the floor is bursting underneath you )

Conclusion:

-spoilers.
I really really REALLY enjoyed this one! Its the best ive played so for of addon maps. Though troughout I had the idea I was stuck in a movie from JJ Abrhams with the lens flare in every single light ( wich is a positive point ) I love the idea to put l4d1 survivors in to help out, and the ending was just amazing. It was crowded though, so that made me lag and when the white screen popped up i though ' Say wha? IM DEAD?' but I survived. Cant wait to play the sequel!! *10 ofcourse!

Pros:

the volcano was absolutley amazing.
the lava was great aswell
great map
enough weps
and cool idea

Cons:

-it is kind of short, maybe you could have do it that they started on the mountain and had to make theyre way to the boathouse, and once they got (where this level starts) in town that the volcano bursts.

-no melees
-sometimes audio skipps ( tried on 2 pcs and both had the problem )

Conclusion:

Its a great map! I defentley recommand it, though , like i said in cons, its kind of short... should have 2 more maps. But really, nice work!