Well I think there is a fine line between dark and scary and unplayable dark
I agree with this, wholeheartedly. I did lighting in theater for a number of years and one of the things that I learned was that "the darker the show, the more lights it had." And it was true! Take a play like "Death of a Salesman," which had a lot of darker scenes that utilized shadows to really bring out the atmosphere that permeated the show. To get those particular shadows, we had to use a LOT of lighting. On the other hand, brighter shows had a relatively low number of lights that were needed. This can be true about any type of media - even these maps.
Scary to me is the flickering of lights and shadows, and the alternating of dark and lit up rooms. That moment when you know you have to leave the lit area, and take that plunge into the dark or face death. There are times that pure darkness has its "terrifying" moments, but if used excessively you'll only end up causing more frustration than actual fright. Remember - even just a lighter's worth of light is enough to really creep the hell out of most people.
I also agree with Gears94 in regards to giving players an
incentive to jump into dark areas. They need ammo? That dark room on their right has it, but there's a chance of getting ambushed by the ceiling or floor spawn points in there. Or maybe they're the last man standing and are forced to kite the last thirty mobs? Create a kiting path with destructible lights and dead ends if they make an early or late turn, forcing them to either stay and make a stand in a lit room or take refuge in the shadows.
After designing the basic structure of these maps, map makers should put themselves in the shoes of the ones taking these maps on. "Wow, if I added this, it'll definitely make things harder" or "Huh, players could definitely abuse this one corner, I'll tweak it and see if it's still bad."
At least, that's my two cents about it.
