Pros:

Long and challenging
Gas cans have new uses
random traps that will toy with you
Alarms trigger hordes

Cons:

Can get annoying when playing with bots

Conclusion:

I absolutely love this short collection of maps. It's like a mixture of Portal and death! I have to admit that my favorite part out of the entire campaign would be the pipe part. My heart was pounding until I finally got charged off into a car... It was hilarious.