I had a run through your map today. It's artistic and easy on the eye. I liked it vary much, but I'm worried about the size.
Some general things:
You have some long stair cases. Its just a personal preference but i would clip all the stairs, making them function as ramps.
I know it doesn't make you go any faster but i like jumping up ramps and stairs. Issue is, if you try to jump up stairs you get stopped (annoying). I don't know how many other people like to do the same.
The ball spawner looks good and functions well. I can also stand in it. I don't know how you want it to function, but i think it would be cool if the player or any props to dissolve if thrown in.
I think your aware, but you have many many missed opportunity's to nodraw. Entire walls and roofs.

Three things about this shot. When i tried to jump the gap from hear i hit the lamp and fell into the trap(peved me).
I've always hated the decal of the pipe you have in hear. It looks like a black sticker with a city street falling out of the bottom of it. It stands out as if you had a pink unicorn in your map.
I know it's next to imposable to get modes to lite evenly in low light situations. You probably be better off with replacing those model concrete tubes with one brush. It be lower in vertexes and textures to render.

I like to be able to jump this gap to, but the ladder caches me and causes me to fall to the ground (taking 10 health). I don't know if you can or even care to remedy this.

brick on brick. Ok, but maybe a different shade.

This looks grate but it look like i should be able to jump in.

Why?

Non solid floor. I got stuck in the doors. Badly. They through me 75 feet down the hall.

These brushes have a small gap between them.