As already said the lights are strange, there is just light, but it comes from nowhere. You need to add a model of a light or some kind of logical light source.
The whole layout of the map is wrong in the a1 version. It looks like you tried to make some kind of open world, you just dump the players in and they have to figure it out.
Try to change the layout so you guide the player. I took a small look at the source for a2 and that looks a bit better.
You have to design the map so that you have larger areas connected with smaller walkways / roads, you can’t just make everything open.
The texture on the terrain is too repetitive, in other words the texture is too tiled, the pattern is too frequent and you can see it. (Especially as a spectator)
Most of the map lacks detail, houses with no doors or windows, no boxes, trucks,…
The doors in the allied spawn are like space doors… wtf?
They also don’t make any sound.
The last axis spawn is too close to the gold. Don’t move it further away from the allied spawn / drop off point though, move it sideways (hope you understand).
It would be better if this was an escort-able truck map and I thought it was at first when I saw the truck at the allied spawn.
The icon for the gold drop off point makes no sense.
The hole in the floor hat goes into the river / sewer is really strange, you put ladders on all the sides, which makes it hard to get down and it is also not clear that the player can climb there maybe remove the “ladders” add a REAL ladder made from brushwork and use that instead.
Most of the buildings look too blocky and most don’t even have a nice roof… and the ones that have a roof the roof is way too flat. I instantly thought you did this to let people walk on them… This is a sucky idea imo (just my opinion) Preferably add a balcony and make the roofs steeper, this will looks nicer and if people still want to walk on the roofs so be it.
Also the roofs on the church are again too “blocky” most roof in real life have an overhang, you did do this on another building, but there the overhang was too small
with overhang I mean this:
Hopefully that gives you a better idea.
As for gameplay, in it’s current state I don’t think this map is ready for a play through.
^ This may seem harsh, but hope it helps.
EDIT: btw the skybox looks fine if you just make it look less like a desert 
To achieve this effect try to change the edges of the map, now they end in open terrain, close some of it up with houses and it’ll look good imo.
Or you could change the skybox to a night sky, then you still have a dark atmosphere and a desert type map. You can then block players at the edge of the map with big rocks / boulders