Great Doom 1 single map wad, for us strange Doom 1 people.
Complex, non-liean design, entertaining ambushes sprinkled around keeping you on your toes, with balanced ammo, and not much health lying around.
This is a very long map, however, (30-50 mins), and it can get a bit boring after a while, especially when it comes to the - otherwise neat, very heavy metal-ish - music.
Do give it a try.
Bland, huge areas, mostly full it, poor item placement and typical Italian emotions in E1M9 because the author could not accept criticism. I think we have come a long way since the troll wad era back in the 2000's, me included. The Gamarra series is pretty much a long forgotten thing over 10 years later.