It would be nice to be able to smoothly walk up these stairs rather than having to jump.
Also, if you're up against the wall while trying to jump up, you bump your head on this sign and can't jump up. I recommend shifting it back or making it nonsolid.
These tanks keep playing their destruction animation on loop for some reason.
If you go into this hallway/shed...
...You get stuck trying to walk down this staircase. You have to crouch to go down it because you bump your head on the ceiling. Raise the roof, bro!
Additionally, most stairs in your map appear to have a slope of 1:1, which is really steep and weird, and as such shouldn't be used too often. Most maps use 2:3, but whatever fits your fancy works.
Weird lighting under the tracks, I recommend disabling shadows.
You've got z-fighting when this door opens.
Don't use the skybox as a wall, as rockets don't explode on them.
Anyway, if you really want plenty of feedback, submit your map to an IMP to get feedback from players.