[OxBlood]

The whole Dr. West-thing is Lovecraft, based on Reanimator (the Lovecraft story, not the movie) and combined with the Charles Dexter Ward-story, the the-world-is-ending-in-a-demonic-eclipse-thing at the end, some of the cross-dimensional ideas, the fleshy-ness of some enemies or locations...many things can be traced back to Lovecraft, though I´m sure he didn´t invent them, he just made them popular and still does to this day.
That´s all I can think of right now as I´m in a hurry...

And concerning scary...I think it´s hard to make anything that L. made really scary these days since his stories just aren´t scary, just mildly unsettling and very atmospheric but I agree that you can´t just throw that stuff into a game and expect it to be awesome. Most references got a smile out of me but not much more.