Sweet, I didn't really even know about this film until my brother told me about it, and finding out that it comes out in a few weeks makes it all the cooler.
Being a fan of the games too (there are four of them out), from what I've seen out of one of the trailers, the movie will stay relatively true to the game. For those of you who don't know, Silent Hill is essentially a modern day town, except it's completely empty. There are very few people there, and plenty of monsters. Lot of cult activities had gone on there (dating back to the American Civil War according to the 2nd game), and the town looked almost as if it was functioning normally and then one day, everyone just seemed to vanish (the 4th game sort of strays from this a little, but it's still somewhat true to the other games).
What makes this game so scary is that first of all, you're essentially in a ghost town, and there's always a heavy fog in the outside areas (this was at first due to the Sony Playstation having limited power, so the game developers had to put it in so the game didn't run slow. However, they also found out that the fog adds to the mysteriousness, and the creepiness factor, so they left it in when the game was released on more powerful game systems), so you can usually only see a few feet in front of you. You also have to go through a lot of dark areas, and although you get a flashlight, you can only see a few feet in front.
To top it off, there is also a radio you can carry around with you. It's broken, so you can't listen to music, but anytime there's a monster nearby, the radio will start crackling static noises. Trust me, you'll freak out when you enter a new room, and hear that thing going off, esp. if there's a lot of monsters in that room with you.
You could turn off the light and radio, and the monsters will be less likely to notice you (they're "attracted" to your radio noise and the flashlight). However, it's kind of hard to see in the dark, and it's not always a good idea, cause then you can't see the monsters either (some of them are transparent, so even with the light on it's hard to detect them).
What really creeped me out was the fact that there appears to be 2 dimensions, a normal one, and a really creepy alternate. What I mean is, for example, one moment you could be in a normal looking schoolhouse, and then the next instant, the schoolhouse could suddenly look like it was straight out of a madman's imagination, with bloody sheets lying around all over, rusty metal gates where the walls used to be, dead bodies lying all over the place (and some of them not quite so dead), and then it could revert back to normal after you've done a few things in that other dimension. It's almost like going through a Stephen King book with your character, and combined with those other things I mentioned, let's just say you probably won't want to play in the dark again for a long time lol.