Pros:

Innovative and interesting setting.
Fast paced and intense.

Cons:

Too short. 
Exceptionally easy to fall to one's death. 
Easy to get turned around and lost. 

Conclusion:

As much as I did enjoy the brief first two slices of the campaign, I'm not exactly ecstatic about further releases, though I won't be avoiding them like the plague either. This custom campaign in my opinion has potential, but it has yet to be realized.