The Good

• Soundscape
• Textures
• Models (although some shadows could be disabled or the shadow lod modified to be more subtle)
• Layout
• Tunnel (Mine tracks are great!)

I didn't spot any real errors in this map aside from a sewing mistake:

And the layout/spacing of paths seems perfect, not all clustered together but allows for a good cat/mouse game when you get to the last few players in the round. I did find some problem areas that would affect gameplay as they could stop folks dead in their tracks rather than allow fluid movement:

For all destroyed walls make a non-solid frame

As for suggestions on things I would personally change; well, that metal exterior ladder on the interior of a building sticks out like a sore thumb, why not have just doubled up on the wooden ladders you've used everywhere else? That and the ladder from empty room to empty room was a bit silly. Gives those rooms some doors or details or something, who would design a building like that heh?

Also, near the CT spawn, that stack of logs could be turned into a ladder entity to speed up movement and maybe make it easier to jump to the broken ledge above that.

Lastly, invisible walls are annoying! I thought I'd be able to jump across rooftops from here but you've blocked me >:(

Believe their is a model kicking around with that sort of style already but something needs to be put there to explain why you can't go on roofs.