Everything from the first, and so much more.
Game play wise it's nearly identical to the first game. For the most part the same moves with Athena's blades are still there with a few extra motions thrown in. The combat system feels as refined as ever though, giving the player the ability to throw huge monsters and pathetic soldiers around with ease. There are plenty of new weapons to take advantage of, though I still always found myself using the blades, and there are also plenty of new power ups to exploit. My favorite new item is the Golden Fleece, which allows you to hurl back enemy attacks. There is nothing like turning a group of monsters to stone with a counter to a medusa's gaze. The Fleece really gives you the feeling that when you block you are doing it for a reason, not just to save yourself. It adds a whole new level to the combat.
The game sounds great and the cut scenes are some of the best that I've ever seen in a game, let alone a PS2 game. The areas are beautiful to look at and for the most part vary considerably. I am constantly impressed at how well a fixed camera can be implemented into the game. Though I occasionally found myself just hitting the square button, the enemies were usually easy to locate and kill. The camera works in a way that really helps with the scope of the game. Everything feels epic. The story is great, though obviously there is a planned sequel judging by the ending. It's not nearly as bad as how Halo 2 ended, but I just felt that the whole game the story was told excellently and the end wasn't as rewarding as I would have liked. It was a very small gripe though.
Much like the first game you could complain about a lack of boss battles. The time spent fighting the colossus at the start of the game is incredible, but don't get used to large scale battles like that. There are more "boss" encounters in the game and they remain fairly challenging, but the scope of these isn't quite as massive as they were in the first God of War. However, the world as a whole feels just as massive, perhaps even more so. You are constantly part of something bigger, much like in the first, but it is just made much more noticeable in this game. Interactivity with the world is great.
The game is on the short side, not as bad as the first one, but still short, however the Challenge of the Titans and other extra play modes/unlockables really add to the depth, not to mention the entire second disc is filled with watchable featurettes. If you liked the first one, you will like this one just the same, if not more. I would suggest this series to anyone who has a PS2. There are games like that that really leave you wondering if there is any reason at all to go next-gen.