Nice map, comments in demo.
Main points of criticism IMO are that I don't like the lighting, it's overall too dark; skill 0 wasn't Easy at all, ie as usual, skill levels weren't differentiated enough; and the gold key directly after the SK door came too quickly, it would have been an opportunity to add more gameplay after the SK door.
Lots of reuse of areas, but that largely didn't bother me. Coming back to the start for the end fight was actually nice.
Lots of ammo, I had 80 rockets at some point and couldn't spend them - I assume this is down to the lack of skill level tweaking.Not enough health on skill 0, same reason I guess.
Nice setting and some of the architecture was *very* nice like the room with the arch and the ruined platforms above and the columns. Very reminescent of old Tomb Raider games. I guess there is a secret up there somewhere, somehow I didn't think of exploring more but I bet it's possible.
Some other architecture was slightly bland, like some of the corridors and the boss fight room for example. There could have been more details in those parts.
Complete lack of traps or puzzles, as far as I can remember. 99% combat and not many interactive elements. The jumping across gaps was nice. Nice broken floors in places.
The map was fun to play anyway and relatively accessible and straightforward, which is good. I liked the moving stairs. The vore fight was good. Monster placement was in general good and made sense.
I liked it, apart from the few points of criticism which you're always gonna get. Good job overall. I wasn't such a big fan of the texture theme though; I think the map could have looked better with different textures and with a bit more light, maybe some colored light, and a different skybox. But that is all down to taste.
It gave me a couple ideas for my own maps, too.
The Quoth monsters... I still have a problem with some of those. Vorelings have too much health; the death guard I don't quite get, why not just use hellknights; the gaunt is OK but a little on the weird side, and the death lord is easy to take advantage of... he is not really a threat when you give the player a rocket launcher and some cover.
I'm not a fan of locking doors behind the player, at least not for a couple measly vorelings. That has to do with the fact that Vorelings are generally annoying though. For a boss fight it is OK.
Flak ogre's spread is huge and very hard to see; often while strafing, you'll move right into one of those spikes, which is counterintuitive. At a large distance, they can be pretty annoying. Their projectiles do quite some damage.
I don't like how the normal shotgun is used for sniping in standard Quake (and Quoth); it feels weird to precision buckshot an ogre over 50 meters.
I can't hold these things against your map though JPL. They are rather problems I have with Quake/Quoth.
So that got a little off topic, but your map is a GJ and I liked it. Some parts are great. I had fun playing it.