This movie could be good, if you've never played the silent hill games. If you have you'll feel frustrated at the inserting of various people/objects/villains from the game being used how they look cool but not how they actually act within the 5 games established lore.
If you're able to put all of that aside, most people will still laugh at the poorly written dialog and predictable scares. Kit Harrington acts his heart out, but he comes across as sometimes awkward which leads to some accidently funny moments. The lead actress does a great job with what was given to her.
The art direction is actually not bad and some of the shots within silent hill are very pretty, but at moments the set direction within small spaces was kind of bizarre mostly outside of the silent hill world, in a distracting from the movie way. The special effects and the monsters look cool, with the exception of the fire which looks like something a 13 year old did on Tumblr. The 3D is well done, and the effects of the ashes and the darkness with the 3D is worth seeing.
However, when the scariest moment of the entire movie (As in the biggest crowd reaction) is a pop tart exiting a toaster, it's not really the best horror flick.
Pros great actors, endless jon snow jokes
Cons bad acting, not that scary, goes off track of real silent hill