Pros: Nice blast from the past. Definitely brought back memories of my dad teaching me to play Wolf3D.
Cons: Can't really think of any cons except possibly lack of cowbell.
Improvements: Needs secret walls, maybe. Might also consider doors that close after a time. The doors I saw in the map stayed open.
Notes: In a zombie horde server, the doors staying open once you open them provides an interesting addition to gameplay because you have to be careful which doors you use because, from then on, the zombies will pass through that door too. Have to watch your back. Still not sure if I would prefer it that way, though. Well done, regardless.