Overall a good survival map. An extermination center is both logical and cool location. : ) I couldn't find any spots to avoid zombie confrontations, nor could I escape the map area, which is always a plus. Good job with the surronding nature as well. Here are some of the things that caught my attention: The map is quite heavy for an older computer to handle. The main reason seems to be the burning corpse pit outside. Facing away from it, I get 40-60 fps. Towards the pit it drops to 15-20 fps, causing noticable stuttering. When I'm right next to those flames, it goes down to just few frames per second. You could try adding a hint brush on the pithole. This way, hopefully, the flames would be hidden when the player can't actually see them. This would improve performance remarkably on older setups. The barnhouse's ammo stash, the ext.center's ladder and the elevator could use some extra lighting to make them more obvious with all that fog. I missed all of those the first time I wandered around the map. Especially the ammo stash in the dark corner of the barnhouse is critical as it's the only one on that side of the map. I would also move the elevator button to the back wall from the side so it won't look like just a dead end. The blood stains from the firing range are visible on the floor outside. This can be fixed by replacing the blood decals closest to the wall with overlays and (if necessary) assigning only the firing range floor as their desired brush. Some of the doors have strangely cast shadows. You could either disable the problematic shadows altogether, use some additional lights to make them more natural or experiment with different lightmap scale values (see "Lightmap" at Valve Developer Community if needed). Also, the houseplant's shadow at the ext.center's confy looking room goes through the wall to the basement stairs' hallway. A more nitpicky thing: I would add a clip brush to both the firing range's corpse pile and the barnhouse's entrance, so that you can access them without jumping in a stairlike manner. They are both just a bit too high to be treated as just small ledges you can run over, and really look (to me) like they wouldn't require any jumping although they do. It can break the immersion a bit to be stopped abruptly in this manner while playing. EDIT: Oh, I forgot one thing. In the examination room with the boomer bodies, the smoke from the basement fire comes through the entrance floor just a tiny bit. Again, not a big issue but easy to fix.