One of the scenes i remember best from playing Doom:
Late night, still discovering episode 2, i enter a pitch black room with my shottie in hand, the door closes behind me, and the next thing i know the light flashes just enough for me to see a demon biting my head off and i almost jump out of my chair ^^.
Anyway, this brings me to my suggestion:
- Variable lighting per map area (monsters/items in dark areas would not be visible unless you were real close or with a light amp). This would include totally dark areas and blinking areas, like 20+ turns dark followed by ten turns light).
- Light amplifying goggles: x turns being able to see in dark areas.
I know this would involve changing the way sight is currently managed, and adding to hit penalty over distance for game balance issues but for me the game is all about what maybe hiding out there...
Other suggestions on the subject:
- new special level: lvl 5-8 "The Halls of the Blind":
severely decreased sight (about 2/3 squares distance), demons/lost souls, an autoloading double shotgun as reward and maybe a surprise (hopefully nasty^^)
- new monster: spectre:
same as a demon except you can only see them when they get real close to you (about 2/3 squares).