An interesting take on E3 McGee - Hell Beneath meets the Innermost Dens. I think the placement isn't quite there yet, though - there's tons of ammo and a crowd of riot control hitscanners that don't really seem like what American would do.
+ The snipers are definitely spot on, especially the ones overlooking the blue key door, so keep those
+ The red key archvile was exactly the type of tactical ambush I'm thinking of, and great design with the revenant nearby. I would tweak the layout a bit so it's further from the similar encounter in Map11
+ McGee philosophy was always making tough encounters with strategic placement, which doesn't work as well here because the enemies wander. The chaingunners in the starting area boardwalk are big offenders. It's an issue I noticed with my own McGee entry (Warp Factor), and I think it needs to be addressed to really hit the mark.
+ Personal taste, but the inner blue key room seemed too much like homage for Map22 + E4M1
+ Likewise, I'd prefer a rocket to a cell gun, especially with the ammo given for it. The entrance could be marked as a secret just to fill out the quota for the level.