A truly beautiful game that follows the artistic standard of Ico well, while also distinquishing itself as unique.
Graphically I don't think you're going to find a game that is the better than Shadow on PS2. It will hold it's own with the best out there, and sets it's own standard. The world is beautiful, the bosses amazing, and the artistic style strong thru it all.
Gameplay is divided really into 2 bits, exporing and fighting the bosses. I can see a lot of people doing little in the way of exploration save what they are required to do, but it can be useful. Lizard tails give you a slight stamina boost. Fruits a slight health boost. Taking a time out to look around and get yourself some goodies can be quite rewarding in that way. Fighting the bosses is something else entirely. Each is strategically unique compared to the others, and the experience of fighting these guys is not to be missed. If I were to complain it would be about the camera. It can on occasion get in the way, but really it's a minor complaint. Even with this minor issue, none of the battles are rendered pure matters of luck or blind movement, but you will be finding yourself more than once probably cursing "hey, stop that, I can't see" as your progress is slowed up.
Sounds a good match for the graphics, with the bosses stomping and crashing their way around the place, but in the end, sound is sound, it suits the game and doesn't get in the way, but doesn't really stand out in its own regard.
As for the value, that's probably Shadow's biggest weakness. A first time play thru will probably run you 10 hours. Once that's done there is hard mode, time attack, and hard time attack to keep you busy, plus a few cute unlockable, including apparently an extra colossus to fight if you beat it all. Still, I must admit it probably isn't going to hold your interest for much longer than a week.
All in all, it's a awesome game that I don't think any PS2 user should miss.