I thought it was fucking awesome, in it's own messed up and incomprehensible way.
It is absolutely true to the spirit of the video game, which unfortunately means that there are some chunks of dialog that seem to be translated badly from japanese, and the poor actors just had to make the best of it. It was, however, highly enjoyable. I largely agree with J. Grant's assessment of it, that it's a must see for horror fans, or people who have played the game, but it has its flaws. Of special interest to me was that the town of Silent Hill was abandoned due to a coal mine fire under the town that was apparently still burning. This was probably drawn from stories the real life town of Centralia, Pennsylvania, which has had a mine fire buring underneath it since 1962.
Yoga is very popular in Silent Hill.
Spoileriffic Wikipedia Article for the Movie.. I'm still trying to make sense of some of the plot.