Pros:

Scripted events
Unique alien-pods
Creepy/eerie scenarios/mood

Cons:

Textures a bit bland
Boxy environments
Some areas too big/bare

Conclusion:

Although this one did not have as detailed environments as a couple of the other space maps, this one stood out to me because of the scripted events. A bay door opens and a spaceship floats in, opening its door to reveal 100s of zombies! Excellent! Then having the alien-esque pods where jockies would pop out at you, loved it. The pyramid battle was a very creepy spot, it seemed very alien. 
It really was like playing through a story, an alien race maybe dabbling or exploring something they shouldn't have, and now there's zombies everywhere. 
And it's a campaign, my favorite game-type. Well worth a play-through.