Interesting threads everyone has written. So many theories! I have always loved movies as much as video games. I have always loved the Silent Hill series. One of my most scariest and favorite movies of all time is "Jacob's Ladder". Funny coincidence is that the creators of Silent Hill were heavily influenced and inspired by "Jacob's Ladder". Only different element I believe Silent Hill is a town that lures in the disturbed, tormented, or wicked.
All the different series shares these common elements with Jacob'e Ladder;
The tortured main character caught between reality and hallucinations/mysterious and dark dimensions refuses to accept death much like Jacob Singer in Jacob's Ladder.
Demons that are pursuing main character are actually memories or trying to set main character free much like demons/strange visions in Jacob's Ladder (ie; such as the evil doctor scene where he tells Jacob Singer he is dead)-similarly to Silent Hill series monsters.
At the end of movie chiropractor/angel Louie said to Jacob: " If you're frightened of dying, and you're holding on, you'll see devils tearing your life away. If you've made your peace, then the devils are really angels, freeing you from the Earth", Cybil Bennet is the guide that helps main character see the truth much like Louie.
Generally Females in these stories represent past lovers, the wife/ex-wife which at different points were portrayed harlots, demons, victims, saviors, or the comforting soul mate.
The parent and child re-uniting at the end symbolize letting go, and accepting death or reality.
All this may only exist in their minds, there are some mixed up memories within the strange worlds. Each time we watch Jacob's Ladder, or play the Silent Hill series-we are taken into a deep disturbing story where we are able to walk away with something horrifically new each time.
Cool connections I thought I'd point out. Again the beauty of these stories are the interpretations each person will walk away with.