It's heavily oriented on the video game Silent Hill 2, with some deviations. If you can look past those and take the movie for what it is, it's not a bad movie. I wish some things were a little clearer, but let's be honest, Silent Hill lives from its mysteries, so I'm fine with that. But just like with the game, you need to think about a lot of things to make sense of them.
As for the sound: The previous movies had top sound design, but in music and in sound effects. For my personal taste this iteration falls a little short of that. It's not bad, just not quite as haunting as I wish it was.
Visuals: The previous movies had incredible creature design and, most of all, presentation and exhibition. While we do see a lot of creatures, my inner creature fanatic wishes there was more of them to see. What we see is great, it's just not enough to feel the constant dread which to me is part of what makes Silent Hill special. The effects are okay but as with many modern movies, they just don't seem as flawless anymore. Especially the misty scenery just does not seem to fit in with the lighting and ambiance of the characters, meaning that it doesn't feel like they're really there.
All in all I can recommend this movie. I'm afraid it won't take the place in my heart that I wish it would.