I recently got the DVD from Netflix (oddly you can buy it on iTunes, but not rent it), and was reminded of how much I REALLY like this film. Roger Avary's script has been heavily criticized for being vague, but... I just don't get it. There are parts where Avary almost spoon feed's you information. How can it possibly be vague? You're pretty much presented with most of the facts by the end of the film, and I think the mysteries that are left is part of what makes Silent Hill so amazing. It reminds me a lot of Kubrick's The Shining in its ambiguous nature. There are a lot of things that Kubrick never allows us answers for, and while Gans does allow us, by the end, to learn a lot of the ins and outs of the mysterious town of Silent Hill, he also leaves us with just as many questions as he does answers.
If I can make one complaint about the film, it's that the back story that is eventually given (in the form of a Super 8-esque flashback sequence) feels a little tacked on, as though the studio was like "Okay, we have to give the audience something". I feel like the back story maybe could have unfolded a little better throughout the film through little clues and meetings with other characters, but that was the choice that was made. It also feels like the whole cult angle is REALLY cliche, but it is based on a video game, and cliche tends to run rampant in video games.
For me, personally, I feel like Silent Hill has some great freak outs, some great scares, amazing atmosphere, and the building blocks of a really interesting story. Why it takes so much flack, I have no idea.