I'm currently working on a multiplayer map for the hl2 mod demons vs humans
http://www.moddb.com/mods/demons-vs-humans
The setting is an old mill and some fantasy forest scenery.
I tell you straight forward that the map has to be so dark, because demons are only visible through the shadow they cast from a flashlight.
The only thoughts i made up about gameplay, were that i wanted to create a few rather large areas with mostly more than one height-level so that the demons are able to flee and do suprise attacks from above. Another thing i integrated into the layout is that all of those areas are quickly accessible through the cave crossing in the middle so that the human team doesn't have to walk for hours to catch up with the demons.
ingame overview:












