I had an Idea like this not to long ago but it was like a Trick or Treat and there would be like 2 wads and one would be a Trick wad with a buch of random stuff and then the Treat wad would be really awsome and stuff.
Sign me up for mapping. Put me uh... End of Week 1 or something... Any time will be fine.
Edit: If you ever played Silent Hill 2 that is a perfect example of how to make a creepy game. I've played it and beat it but when I go and play it again I am still on edge even though I know that some of the monsters are pathetic and easy to avoid. Its all in the enviroment and the random sounds thats gets you thinking WTF.