SImply amazing
In all the years I've played video games I don't think I've ever seen a sequel improve upon it's predecessor in such a vast way. As good as the original game was this was simply completely outdoes it in almost every way. First of all I think one of the strongest points to mention is that the game essentially has no filler action. Every sequence of the game feels purposeful and well designed, and you almost never feel any reason to put down the controller.
On top of the game playing well, it also happens to be probably the BEST LOOKING game I've ever seen, the environments are varied significantly more than the original, but every spot in the game feels like a masterfully put together set piece.
I'd go further, but you probably don't need me to convince you to get this, it's completely deserving of all the credit it's been getting, and if your a PS3 owner, then this is an absolute must buy.