Relatively nice design.
The map in general seems open in some parts[like the area inside the stacked crates or the middle area].
You only used about 2-3 textures for the map[not including the crates].
Some crates are a little bit high enough for me not to see the enemies head which makes it annoying that you have to walk behind the area of the crates to shoot.
Fill the open area with props.
Use more textures on the map.
Reduce the height of the crates enough for the player to see the enemies head.
I also found a block near the pillar that was misaligned
so you might want to fix that.
Overall good job!