Had to play this a few times to know exactly what to think about this map...
First off, yes, this is definitely a brilliant concept, and I fully expect a lot of
"most awesome map ever" comments. And those comments would be justified to some extend, while not overall in my oppinion.
The major issue here is that if you focus the entire awesomeness of a map on one thing (the upside-down-portals), you better make sure that thing is truely awesome. And unfortunately, it's not. For multiple reasons:
First and most obvious, hitscan weapons like Shock, Sniper and Minigun don't penetrate WarpZones. Of course I know, that's always been the case, but it only becomes an evident problem in a map like this: The distences when looking at an enemy through the portals are damn huge, so in order to have any chance of hitting them, you would
need working hitscan weapons. Firing rockets or Flak shells through the portals won't do anything, your target will never stay still long enough to hit it. Plus, it just breaks the immersion when some weapons just don't work "for no reason".
And since hitscan fire just performs a simple trace function which could in theory be mirrored to the other portal, I'm very sure that with enough scripting effort, this problem could have been solved. At least for the vanilla UT weapons that is. Making hitscan fire work for
every custom weapon might be extremely difficult, if even possible. Still, for the four affected default weapons, this should have been done.
Second, the upside-down-portals are basically high-poly-decoration. There is - especially without working hitscan - no real reason to even try to use them. You can't really kill enemies through them, and besides the jump boots and maybe impact jumps, you have no way of getting though either. So besides trying to get a few free kills with the Redeemer once a minute, I really don't see a point in using the portals at all.
And third, the transition through the portals -
if you decide to use them - is pretty ugly. I would have loved to see a smooth turning of the player's vision, instead of just flipping it around from one frame to the next. Sure, that would have also required a ton of scripting, but having good old 2006's "Prey" in mind, it would have been worth it.
Now aside those portals, what else can I say... The overall layout is fine, I just don't like all those corridors at the edges of the map too much. Plus, it's very confusing to find your way around, since everything looks the same given by the choice of style. As for the style itself, I kinda like it. It's hard to make a "no textures just lighting" map look good, but it works here. The translucent wireframe-weapons are a nice touch, though I don't like the fact that after picking them up, the 1st-person-model has its default skin again. Of course, I won't judge you for NOT going through the nightmare of reskinning those animated models... I would have been to lazy to do that as well for sure. But still, it feels inconstistent if you just look at it from an aesthetical point of view. I very much like the 2D-sprites for pickups though, but there's one easy-to-fix flaw here: The ShieldBelt icon says "+100", while providing 150 armor.
Now, reading my post again, I feel it might sound too negative... It shouldn't. Overall this is still a damn cool map with a truely unique approach both in style and in gameplay. All I'm saying is that you should heavily consider to release a "version 2" some day, and invest probably a lot of time into scripting, in order to turn this "cool map" into the masterpiece it could very well be.
Here are the screenshots! 
. The only big downside I could find is that map is very confusing due the generic, over-repetitive textures. 
players would do the same.
