Not so great screenshots, be sure to use the commands "/hidehud 1" and "hudgun 0" when taking screenshots for maps (as the hud and hudguns aren't part of the map at all).

Theming
The theme, well it's seems to be industrial, but it's not convincing me, because of several points which will be notified under this line of text.

Texturing
It seems like you've used a bit of all textureset which are inside Sauerbraten. Not a great idea as some only have a diffuse texture, while others have a bump-, specular-, height- and even glow-mapped texture next to the diffuse texture. This creates most of the times very weird feeling, as some textures do have certain depth, while others are just flat.
Be sure to keep just a few sets. Like replacing the techsoc textures for something like the lunaran textures (or the unofficial eX-texture pack).
I would advice you to check out the map "industry" and a map like "hades", to get an idea of what I mean.

Geometry
The geometry isn't great. In the centre are just 4 misshaped silos (as some of them aren't round at all. If this would be intended, be sure it's not just 1 perfect strip) which aren't textured very well (as you've used a texture which is commonly used for trimming).
Even you've added some landscape into the ground, the ditch in the centre is just 1 perfect strip. It's really ruins the atmosphere.
The map itself seems just a matter of copy-mirror-paste, which isn't giving a great result.

Lighting
It seems you've added an intense sunbeam somewhere in the sky, but the skybox isn't giving a realistic result (as there is no sun at all).
Also, use "light 0 255 107 0" instead of "light 3510 255 107", as it looks very unprofessional.
You've added lights at light-sources (well done, as most new beings around here forget that point), but they are conflicting other lights with pretty odd results.
You ever heard of "entselsnap" for positioning entities like lights, weapons, playerstarts, flags, etc? It makes you move entities on a certain grid, instead of freely. Very useful for lighting, positioning models or making the gameplay balanced. It has been bind default on "6" in edit-mode.

Detailing
The map has some detail, as prints of the balcony-paths (couldn't find another word for it). But it's missing the detail what makes it an industry. Come up with some logical ideas and add them into the map.

Clipping/Noclipping
Well, you've created a clipping barrier so players can't get out of the map (which is also remarkable for a newcomer), but be sure to texture all the outside surfaces which players are unable to see. They don't have any purpose at all as players can't see them anyways.

Flow
The flow isn't very great, as the map just consist out of 2 layers of platforms. Be sure to add more layers so it won't be just simple and boring as it is now.

Gameplay
As stated before, learn to use the "entselsnap" command. Also, observate other maps how to place pickups properly, as you've placed them just randomly.
A hint for that is; keep players being hungry for health and armour, but let them always be packed with some ammo.
This means you have to place a low amount of armour and health and a subtle amount of ammo.

The map isn't great yet, but could be improved. I won't rate it yet.