Hard and weird. By hard I mean you do not have much ammo. Not much fun.

There is an earlier version of this map in http://www.quaddicted.com/filebase/trash/pandem01.zip

From a quick look only two bytes are different and it seems to be the audio track. So I tried to remain calm and put it into the trash directory instead of adding it.

It's clearly a dm map, but quite an interesting one at that. There are some nicely creative ideas on offer here. I can see why the author was offered a job as a map designer at Ion Storm.

As a single player map, the map's kind of unforgiving at the start. I was playing quite sloppily and had some bad luck, and so kept dying at the beginning over and over again.

At one point I didn't know where I was supposed to go, and spent quite a few minutes just wandering aimlessly, until I was able to find my way out, so that wasn't very fun. But the cool architecture and challenging combat kept me entertained enough without it managing to overstay its welcome too much.