The best way to describe the look of Siren is surreal. Take the best parts of every survival horror game you've ever played and you'd have a good idea of just how the game looks. This isn't to say that the game is a graphical powerhouse, but it manages to create its own style -- a trait that is always welcome in my eyes. The overall look of the game is very, very bleak and, in a way, called to mind old horror-movie footage from the 80's that has degraded over the years. The level of detail is kept very low and there's a definite blur and flatness present. Some might point it out as once again showing off the PS2's biggest graphical shortcoming, but this is to the game's advantage.
The one aspect I didn't enjoy that much were the character models. Character detail is on par with those found in the game's environments, but they don't work nearly as well on characters. Their animations are also thrown off and feel too stiff at times.
Sound is one of the key elements of any survival horror game, or anything horror related in that case. The experience in Siren is one of the creepiest I've heard in awhile and ranks second to those found in Fatal Frame 2. Every sound in the game has a realistic, yet creepy feel. The music even helps to build on this. The downside to the entire thing is the only aspect in the sound department you're likely to remember is the terrible voice acting. This is easily the worst voice acting I've ever heard in a game and if I could have turned it off, I would have. But then again, I'd miss the other sounds.