Abyss.wad  -- this file should be ok now, I hope!
This pwad was written by Avery Lodato (alodato@ucdavis.edu) using deu5.0 
and bsp1.0.  It replaces E1M1.  Designed for single player action, I 
would give it difficulty factor of around 7 on a scale of 1 to 10.