Chasm is a nice little map set up in a rundown mining town, or something like that. The urban decay thing is pulled off well. Textures amplify this run-down look well. Lighting is dark. I can't tell you how many times I cried out for a flashlight, searchlight, or even a match.
Construction is solid.
The author does note some HOM from a few angles, and I caught one of them. Otherwise it's not noticeable at all. Also caught a wierd bug where someone could basically stand on the sheer cliff of the chasm and take pot shots at people running across the bridge, at least until their ammo ran out. Bots use all three paths to and from each base, and they usually put up a pretty good fight. Especially when you've got their flag.