The environment lighting seems really weird, like it's being projected horizontally or from below the map.
There also seems to be quite a few sightlines, mainly the one from the platform with the small ammo in the second screenshot to the left BLU door on the other side of the map (in the same screenshot).
It does also look a little small, although I can't tell for sure. There should probably be some sort of buffer-like area between the spawns and the main arena to prevent immediate direct sightlines and improve general balance.
There should probably be more paths up to the middle ground from the lower ground, from the screenshots I can only tell that there's 1 such path for each team.
Also, something cool to think about - angling the roof of the center building, lowering it, adding holes, and making it able to be jumped/walked up on - would provide some interesting vertical combat and something along the lines of the center of arena_ravine or watchtower.
