This custom Campaign i just finished was hard and creeps me out mostly. For the last 2 missions each mission there is a constant wave of enemies but the last 2 were the worst mostly for the Khnum's both missions had a certain amount last mission had like 40 of them. I hate when they are close to you because it chase you when they get to you they crush you which = a instant death. So for anyone who plays Serious Sam 3 and hasn't played Approaching Hell get ready for some crazy stuff in that campaign. I give it a 10/10 on the creativity and a 8.5/10 for the difficulty.