Pros:

the bosses are unexpected and creative
the level design is fantastic and strange
the atmosphere is very extraterrestrial

Cons:

it gets a little confusing at times 
there is no indication if it is your first time playing how to kill the bosses
there could have been more guns and ammo stashes 

Conclusion:

this map is very fun for l4d it has bosses that would never be in the regular game and the bosses are so creative and at times a little scary i love the space thing overall this is a good map and it may have some faults but it is very fun i suggest download it is worth it

Pros:

good

Cons:

god

Conclusion:

it looks cool but i cant find it on l4d2 i look on the developer console and all of the games addon campaigns