At the moment, I'm reworking the enemy placements, improving some architecture details and trying to add more shading in certain places (especially the big outdoor areas). I am also trying to reduce the framerate issues in polymer mode with different textures in some places (one of the bathroom-textures is very reflective and seems to need a lot of GPU-time, like the bathroom in the original E1L1 map).
As I said, I tested the map with a friend (not a "Duker" before that), and he gave me about the same feedback as I got here. So I'll try to fix all of these issues. Of course it will not become another "It lives" (or similar masterpiece), but I hope the enjoyment outweights the flaws in the final version

. It will take some more days, and I will post it here again, when It's done.
The map had a good sense of progression and variety; cave, high tech, alien, outdoor so it felt nice and full which is good. Because I was playing with polymer there were framerate issues at times. For example around that big alien spaceship in the lake, I died many times because there was so much going on that it dragged the framerate down.
Thanks. On my machine (it's quite fast), I have framerate issues in the first two bathrooms (as long as the mirrors are intact) and the central command. But I experienced worse in some of the original maps (like DukeBurger, again near the bathrooms). Maybe that gets better with further developement of the polymer-mode in future releases.
Note that turrets are framerate killers; they shoot lots of laser sprites, and those sprites all generate polymer lights, so all that plus the TWO battlelords (I was playing on the easiest setting, might want to tone that down a bit) and the dozens of other enemies, including troopers which also shoot that resource intensive laser sprite really resulted in a lot of unfair deaths. So yeah I'd restrict one of those battlelords and the turrets to a higher up skill level.
I placed most of the turrents years ago, before polymer came out. But I removed some of them lately.
Also found the boss battle at the end pretty difficult, there wasn't a lot of room to move or much cover to hide behind IIRC.
That's because I wanted to fit all the ships internals (lower and upper deck) in the shape that you see on the outside. So yeah, it is unusual tight for a boss battle. I added two doors rescently to get more cover. There is also a hidden switch where you can deactivate the forcefield and get the boss into his oversized teleporter. With some luck, you can lure him to the ship's outside. But that was just some sort of experiment to test if bosses can be teleported (yes, they can).
The only problems from a technical point of view were some slightly stretched textures in the elevators, and in the WC in the mess hall, when the swing door was closed, it caused the normal map on the floor to go all funky and the sector didn't receive polymer light (not sure but it might be due to possible overlapping sectors, but if you can't fix it it's not a big deal since most non-mappers wouldn't notice).
I will check the elevator textures. For the sector-problem I didn't find any solution yet (it happens in the first two bathrooms and the left officers quarter). Maybe some experienced mapper has an idea.
Unlike Forge I did enjoy the gameplay. Sometimes it just feels nice to wander around a bit, and I never got too lost (the automap was invaluable in the cave), and there was more than enough ammo.
Like I said, it seems to be always an opinion kind of thing. There are some usermaps out there that are simply excellent masterpieces in terms of details, features, architecture and balance. I think I would never have the patience or creativity for something like that. But they are not always as enjoyable to me in terms of gameplay and excitement as some of the more simplistic classics. But even in that case, I enjoy the eyecandy.
I remember the first usermaps back in 1996 (you could buy lots of CD-ROMs with hundrets of usermaps, even the game itself was banned shortly after release in Germany because of it's violence), and 95% of them were really bad in terms of texturing and especially scaling. For example, most of these maps had 15 feet strippers, 10 feet toilet bowls, 5 feet light switches and other things like that. The BUILD-usermapping has come a long way thought the years

... I still own two or three of these CD-ROMs. Maybe I take a look and find some long lost classics which are not on the internet anymore (but as I said, 95% aren't interesting anymore by todays standards).
As for the shading, like I said put more lights in the cave. And even though the map uses polymer lighting, you should always use a bit of manual shading as well. Different areas should have different overall shades (especially indoor vs outdoor), and adjacent walls as well as ceilings should have a few shades' difference between them as this helps give the map more depth.
We'll see what I can improve there.
Still, an enjoyable map, I'd give it perhaps an 85 out of 100. I really look forward to your next map 
Thx, thats really generous.
