If you are looking for a good horror game, look somewhere else.
Saw II in my opinion is below average in all sub-categories.
Graphics: Simply unacceptable. Low resolution, low detailed and covered by darkness. Okay, they are "functional", but one would expect so much more from a PS3 game.
Sound: Nothing special, though the voice over of Jigsaw is good.
Atmosphere: A horror game that doesn't scare you. In fact it doesn't ever try to. And it isn't gory either. Underwhelming all the way.
Story: You can say that it has a little interest, a little I repeat, but the ending is so lame, it so ridiculous, that it feels like a bad joke.
Game-play: With one word: annoying. Hundreds of identical mini puzzles that serve no other purpose than to slow you down and make you mad. Very few, probably four, or five of them are notable. The boss battle-puzzles are okay, but towards the end they become very difficult, if not frustrating and will surely make you swear. (if you didn't listen to the warnings and still bought this game.) Also the same annoyances from the first game are still present: For some reason the developers thought that the barefoot character that steps all the time on broken glasses is a good idea and so they included it in the sequel...
Some new additions, while they were welcomed, or at least neutral at the beginning, like the madman with the spikes for instance, if you face them 6 times, it isn't fun any more. It's pure annoyance. The same can be said for the puzzles too. By the way, I think that the puzzles of the first game were much more challenging and interesting.
Also the battle function with other characters was replaced by a mini-game, which I also found very disappointing.
Conclusion: From roughly 12 hours of playing, for the most part I was in a state of anger, or boredom and from times to times I felt a mild interest for some puzzles. This is not my idea for a good game.