Pros:

-Challenging and creative

-Interesting finale

-I enjoyed the scarcity of weapons, it added to the challenge and forced us to conserve ammo for the important parts; made finding ammo caches all more satisfying.

-Really fun to play with friends, had a blast

Cons:

-I'm not really too big a fan of random guessing for "puzzles"

-The final map can be pretty cruel; it's a really long run with infinite spawning mobs.

-The overall design/use of texture could use a little more consistency; the transition to the stone maze in map 2 felt a little off.

-Had an error in the addon campaign select screen and a missing texture for its image, noting game breaking though.

Conclusion:

Overall it was pretty fun with a few quirks, nothing too bad.  Be aware that at times, a lot of luck and guess work is involved.  I'd suggest playing the last map on normal, unless you have a really good team, it's a real tough one.