Lot of space for improvement, though.
Some tex misalignments especially around stairs edges and on the slope leading to the 1st vore.
Gameplay is indeed a little on the easy side, I suggest you'd remove the last shambler and have him teleport in when you get the gold key. After that, a huge monster+ammo+(item) spawn may start a battle royale to round things off. Otherwise, after the gold key, the action's over...
Sk3 demo.
http://www.quaketastic.com/upload/files/demos/toabeta_1stnm_thesilent.zip
Nice work overall...