This is a Ravenholmish map and I really like it. There are two distinct parts, the onslaught and the sewers. First you have to survive three (if I remember right) minutes in a zombie invasion. I think the map layout here is perfect for this kind of stuff. It’s very fun but not very hard. The sewers are really cool especially since they have secret areas. It’s pretty fun. The only complaint I have is how many headcrabs there are in the final combat area. I wouldn’t mind this if it weren’t for that there’s all three types so it’s easy to have a cheap death from the poison/fast headcrab combo. Without spoiling anything the ending is cool too. I recommend this map.