There are tons of technical problems on your map unfortunately, the layout and some brushwork is really nice aside from near end when this intricate brushwork turns to just several square tunnels. Combat encounters are ok too.
First major sin is that one of your stairs is clipped as a ramp, that is a big no-no. Other clipping issues that are frowned upon is to make invisible walls on clearly traversable paths, these windows above exterior area. Get creative with some way to block player getting a shortcut. Some of the walls that would've benefited from being clipped were not clipped. Like clipping was inconsistent overall.
Doors didn't have alcoves where they open into, its a bit jarring with base doors. Some doors caused z-fighting on the outside walls. Some window ledges had prototype textures, same with some monster closet walls.
In the sewer area it can be a bit annoying to travel all the way back to that one spot where you can get back up from the water. After jumping over the gate if you fall to water there, you will be stuck as there is no lift on that side.
Lift near the other button at the sewers that opens path forward is not visually shown because it is under the regular floor.
After you get grenade launcher you can blow up every monster with it because there is just so much rocket ammo.
Phew, hope you get all of these obvious problems fixed, because the map is fine otherwise!
