The fighters loved rolling two dice!
When I described the faceless priests to them my seven year old put a scared look on his face and then said, "Dad! Are you trying to scare me?" Of course I answered, "Yes."
Later when they killed one of the faceless priests and a multi-legged thing came out, he nearly screamed! So I had it run down into the pit. I don't want him sleeping in my bed tonight.
Not a huge play test, but I think you guys got the atmosphere of Appendix N down right!