Wow! Awesome mod, love it. I tried to create an atmosphere/feeling similar to this in my maps but this is on a whole 'nother level! Congrats.
Also, I found a bug. You can do a linedef skip and run into a bunch of enemies that look "dormant". Its near the final secret of the catacombs. You can fix this issue if you increase the floor height of sector #9693. ;)
D-27
joined
Hope rides alone.