Best action game on ps2. Period.
The game's soundtrack is something to be appreacited too, especially given the mythological theme. It has been a long time since I saw a game that really hits the nail straight. In God of War's case, the soundtrack switches from an upbeat action theme to the moody pathos that Greek mythology likes to vary inbetween. This is a soundtrack that sticks in your head, but as opposed to many others, it doesn't bother you.
There is more to the game than just graphical and sonical excellence though. There's the unique gameplay, that relies on much more than just button bashing. Sometimes you'll be totally overwhelmed by enemies, and you'll have to play it smart in order to survive. Different kinds of enemies demand different tactics, and the game's deep combo system really comes into play here. Learn those moves, and find out which kind of combo works best against which kind of enemy. Know whether to tackle an enemy up close, or from a bit further away (your main weapon having quite a long reach), and which kind of magic to use in which case.
The game doesn't just throw enemies at you. There also are various puzzles that you'll have to solve. I really found these puzzles to be very interesting, and they integrate nicely into the mythology theme. Some of the later ones are timebased, and you'll have a hard time getting through, but none of them are impossible.
The interaction in this game reaches an even higher level thanks to the way you can use to finish off enemies. As soon as they're low on energy, the "O" symbol will appear above their head. You can then press the "O" button while close to them. This will trigger button combinations to appear on the screen, and if you time all of them right, you can finish off your foe in a nice, nasty way. Not that the game lacks blood and gore: it already has that in abundance. The interesting thing about these finishers though is that they will grant you life and/or magic gems, so they can be a tactical choice.
Also worthy of noting is that Kratos isn't your average kind of hero. Here is a guy with a lot of darkness and anger within him. The kind of hero who isn't too shy to get rid of an innocent victim in order to reach his goal. He also has quite an evil past behind him, something which will be made clear as you make progress in the game, and leading to the best story in a ps2 action game so far.
There also are several bonuses to be found on the dvd, including a making of, new challenges, and costumes for Kratos. Some of these can only be unlocked after completing the game in a certain difficulty, but it's good that you have to work for your dough.
To sum it up: top title. With God of War being a budget title now, there is no excuse not to own it.