Sweet-as-pie slice of some classic feeling Q1SP, really enjoyed my time.
Semi-blind NM demo here, played in QS 9.83.1

As for criticism, I really didn't enjoy that water bit (limiting movement like that especially in Nightmare makes for some really annoying fights) and I felt like you could have milked that finale a bit more, a few grenades and the boys went down. 

First time playing the final release although I playtested the earlier versions! Sucked at finding the secrets. Great map, well done! :)

https://www.youtube.com/watch?v=xaVIt4cPJWk 

I had a great deal of fun in this map. My favorite thing about this map is the cover placement... Boxes, support beams, etc. There would be an ogre/dog/fiend to come and push me out of the cover spot. But since there were multiple options for cover, it was possible to run to a new spot. All this created a dynamic feel for each room/battle which I really enjoyed.

The hardest part was the water-filled room Fairweather mentioned. On skill 1, this was the most intense section of the map.

The RL secret was simple but very clever... Just happened to find it by luck.

Normal difficulty
20 minute clear-time
3 secrets
100% kills
3 deaths 

Speaking of cover (sort of), the stairway combat setpiece was a neat twist on that sort of thing. The central platforms with their narrow spacing really changed it up. 

a fun blast. Here is my demo:
http://www.quaketastic.com/files/demos/off_ankh_01.7z 

I liked the water section, especially because you had to navigate through it _without_ a grenade launcher. Felt like a very time-sensitive maze. A refreshing mechanic that you don't really see very often. The whole map had some neat ideas even after 25 years of base maps. 

...in the water section. One close at the beginning and one further down the path, in case you miss the first one. The first one has four lights aimed at it too; however, I am guessing the enemy encounter has some folks distracted :) 

Nice map indeed and good to see a standalone release. After the cramp fest that was xmasjam2019 I thought I was playing Warpspasm. No offense, can still appreciate the mapping challenge, just prefer a bit more wiggle room, like here. 

Very interesting release, and not just because standalone id1 maps are rare nowadays.

The first noticeable thing is how the map chooses to use simple (but striking) shapes for the architecture, and then applies highly detailed textures onto those shapes. It's a clever extrapolation of what id was doing with the same textures in 1996, just on a different scale - and something of an antithesis to the detail-by-complex-brushwork style. (Which was so prevalent this decade, going back to Rubicon 2, and possibly Ruined Nation before that.)

The texture combinations were interesting too, as there was a lot more to them than just idbase + Rubicon. (Don't think the RRP toxic box signage escaped my eye.) In most cases it was 90% idbase and 10% other stuff, which lent itself to giving the map a "Quake+" vibe.

I liked that there was some considerable variety in each major encounter, with the usual order of things being a little tilted - it's not often you see a horde of Grunts after battling multiple Ogres and Fiends.

I wasn't sold on the flooded Zombie basement myself, mainly because of the liquid impeding my movement against the Voreballs. Mapping protip: you can get away with controversial encounters like that simply by placing a megahealth beforehand. ;-)

Here's a double skill 2 demo with outstandingly lazy play and multiple lapses of judgment (sorry). I enjoyed the map a lot regardless. 

Good work. Just finished playing this, and I think this has replay value. Halfway through this I realised this is the kind of level that I would like to revisit. The architecture while perhaps not as detailed as other levels, was still effective in conveying a convincing sense of place. I liked that the combat encounters were well thought out and staged.

It could perhaps have been a touch tougher, but I never got bored.

I think the flooded basement section was a highlight of the map. It looked good with the strip lighting at the top, and the encounter itself was challenging with lots of zombie gibbin' fun. 

...as well as BoraxMan, Johnny Law, maiden, Nyoei, Tintin, and (of course) zigi: thank you for all the feedback! I was away for the holidays and couldn't reply sooner. I look forward to checking out these demos and greatly appreciate the input.

For anyone having problems finding secrets (or curious), I noticed that VoidForce[Dissector] did a nightmare playthrough of my map on YouTube where he found them all like a champ: https://www.youtube.com/watch?v=6Htzz5UOxVo&t=57s 

Highly enjoyed this, hope to see more from you

Blind Playthrough here

https://youtu.be/uYxLk7sRlsY 

Here is my demo:
http://www.quaketastic.com/files/demos/red_offbase.zip

Neat old school style base map.
Some very fun and unpredictable encounters here.
The ending was as challenging or climactic as some of the earlier fights though.

Good job.