It's too bad my comment was erased with the creation of this thread,
but hopefully you remember what I pointed out. In case you
don't... here it is again... except with pictures!
Like I said before your two main problems were not enough lighting and
not enough connectivity. I already suggested ways to improve the
connectivity, but here are some shots of areas that need lighting:

This
is kind of ridiculous. All I can make out is a wooden box. You
need some sort of lighting here. Just in case you can't tell
where this is, I'm facing a corner where if you walk up to it and turn
right you're looking down this straight hall:
The glows on those lights are really way too big and bright. Tone it down a bit, it's very distracting.
I liked this room for some reason. Although it was kind of weird
to have a combine console in the same room as the Resistance type
computer set up. I liked that this is where you get the
ar2. Like I said in the comments thread I think it would work out
will if you connected the back of this room to another area of the map.
This is looking back down the hall. You need some lights on the
ceiling because I can't see much. All the work you're doing to
make the ceiling look interesting is going to waste if it's so dark.
I feel like I'm looking at the face of God. That thing is so blindingly bright. Tone it down to a third of that.
I like your usage of the spot light effect. The direction of the
beams does seem a little strange. Shouldn't they be pointing to
different places on the same x axis? Also, I didn't understand
why you had those platforms holding up barrels and boxes on the
wall. I appreciate your attempt to make the wall interesting,
but... that just didn't make much sense as a storage place.
Perhaps you could make a recess in the wall with rolled up shutters
that contain the boxes and explosive barrels. That at least would
make more sense.
I prop jumped up here in a couple seconds, and I realized this would be
a pretty good camping spot considering how dark it is in this room and
the fact that a crossbow spawns a little bit below me. Some more
lights would discourage this type of deviousness (and the frustration
that it would cause for the victims :biggrin: )
I don't know if others can see what I'm talking about but I really
liked the temperature effect coming out of this grille. I wish
you had used this in more places around the map. It's just a
snazzy use of the Source engine. Your map is small enough and
runs smooth enough that you can afford to put some more of these nice
aesthetic details in.
Once again, you need more lighting, and you need to cut down the glow
effect. This room should be connected to another area to
eliminate the dead end. I noticed the swamp room was directly
below this. Perhaps a ventilation shaft with a ladder connecting
these to areas? This room would also benefit from more
prop_physics and some loose trash. It's too clean and empty right
now. Try adding some geometry to the walls. Trims, recessed
lighting... or just something else to spice this room up.
Daaaark. Aside from the ceiling and the spotlight this area kind
of boring. You can fix this with more interesting textures or
some subtle geometry changes.
Thankfully this area was well lit (the only one that I thought was
bright enough). The smoke coming out of the pipes was way too
thick so when it disappeared it looked strange. Try making the
clouds less dense.
I could not figure out how to get that healthkit or battery.

These two decals looked awkward. Perhaps you could make a thin
cylindrical brush poking out of the wall so it doesn't look so flat.
This area has some potential. Apart from it being too dark there
are a couple things wrong with it. First off, I liked the
idea of a dirty sewer type area, but... what's with the grass? I
don't see any sunlight. Also -- the ventilation duct looks out of
place. I'm not sure what you would replace it with... perhaps
that ladder I mentioned in the shotgun room.
I liked the idea of having weapons/ammo/health that you can only reach
with the gravity gun, but I wish they were a bit closer. In a
combat situation I wouldn't want to have to wait around while I slowly
pull the crossbow down the loooong tube.

I like the vertical nature of this area. Again I wish it were
brighter. Maybe some spot lights shining down from that upper
area? Or a brighter shaft of light coming down from that grate?
I thought this corridor was too dark and too thin. Any battles
here would be pretty boring because the hallway is so long and there's
no cover.
That just looks bad. Move the props or the geometry.
The natural light seems way too dark. Brighten it up, because
while the dust motes are a nice touch they don't seem believable in
such weak lighting. The room itself is also way too dark.
If a brighter light environment doesn't fix it, then add some more
light fixtures. The glow coming from the combine consoles isn't
enough.
Anyway -- work on the lighting and connectivity and this map will look and play much better.
Keep it up, looking forward to the next beta.