If you've played a God of War game you already know what to expect.
If you've played either of the first two and you liked them then you'll definitely like this. If you haven't played the first two, I recommend you start there first because the story is quite enjoyable between the three.
This game does a lot of things right. It gives you big sized gaming in good chunks. Where some "portable" games actually make you feel like you need to sit down and devote a good amount of time to them to really play them, I never felt locked down with this game. I felt like I could play it as I wanted and then go about my business.
Yet it still brought that feel that the PS2 games brought on where you felt extremely powerful and fought tons of dudes all at once. After all, you are the God of War so this is exactly how things should feel. I also can't remember any times in this game where I really felt annoyed at the task that I had to complete.
The difficulty on this game felt a bit lower than the other games and I'm not sure if the game itself was easier, the PSP's limitations caused them to be able to do less and in turn it felt easier, or if the formula has just become so second nature that the challenge has drained out of it. It didn't really bother me, but I guess it's something to note. There are always higher difficulties to if you're really looking for a challenge.
So, the biggest fallback of this game is probably it's length. Coming in at only 4-5 hours this game can be played in 1 good sitting or 2-3 short ones. If you're only playing it while you're on the go you'll probably get a lot more sittings than that. But chances are if you're playing it for the story you'll end up doing it pretty quick. There's not really much extra to do either. There are the usual challenges, but the main game is pretty quick.
So, I didn't want to bore anyone with the gameplay features because I assure you they are right on par with the other games in the series and the majority of people looking into this game probably won't even read reviews because it's GoW so there's no use me even wasting my time going into it. Definitely worth picking up, one of the most enjoyable PSP experiences to date. Don't miss it.