Felt like a submachine game. Loved it. The secrets, I barely found two (and one was by accident), really hard! loved that. I'm going to replay soon and see if I can find more. 

Holy cow what a level!

Skill 2 - 4/10 secrets
https://copy.com/qw6cHOkmv8cUnPoV

The start is a bit rough with the overpopulation of enemies just standing around but the level quickly delves into this otherworldly complex that just makes you feel...isolated!

Hard was pretty challenging with just the right amount of ammo and I never felt things were unfair or too easy. I felt a bit overwhelmed with all of the teleporters but with the signage and overall direction I made it through. I think the first gold key gate could confuse people since you have to go through both sides.

Just when I thought I was out, there is the final portion of the map which just ups the difficulty and then some! You will see in the demo that I almost take the cake at the very final fight! I tried to get cocky with an attempted infight and that backfired! Was exhilarating to say the least. Secrets were marked well, I just couldn't find the other 6 haha.

I loved what you did with the silver keys and the four button puzzle.

Excellent job done digs! 

Could you please post a demo with all secrets revealed? That quad secret in green room drives me crazy ): 

A little bit later :) 

this was a fun map, I loved the architecture and lighting even though I think you used every texture in id.wad :P

Couple of little critiques,
-some of the centreprints felt a little heavy-handed
-not sure about placing every enemy with their back facing you, seemed weird

have demo!

http://www.quaketastic.com/files/demos/5thdigs8.zip