It's a good map,but the degree of difficulty is variable

Normal:
Under this difficulty,too few corpses make it easy and smooth to finish——especially tanks and witches are too weak to threaten the suvivors.It's more like a tourism.(The third chapter's skybox is wonderful,I think)But you may get bored if you don't like the view.

Expert:
In this map,the amount of tanks and witches is more than average.So it's harder to deal with each of them perfectly,and bots will fall from the ladder or some strange places and die(many maps have this problem,maybe I should finish it without bots).The rescue is too long,I must spend a lot of time runing and running after die many times(I'm a noob,can't deal with 3 tanks and 2 witches)