Ok I just picked this game up last night. Target had it for 32 bucks (It was also the last Xbox copy too SALES GIANT) so I figure I would take a chance on it. I've played it for about an hour, and as soon as I saw that CGI ass walk up the steps I told myself I wouldn't let the setting get me down. As an aside, I'd rather see a chick with a nice body and showing it off as a protaganist than a half naked male. Anyway, back to the game, the combat is better. I do like the free form combat system but I think there are things that can make it better. First of all, the amount of attacks is nice, but in a way the fighting in this game reminds me of Mortal Kombat in the mindset that all the attacks are preset canned combos. It isn't just the attacks, but the animation is a bit stiff too in the same way. On the other hand, Ninja Gaiden reminds me more like street fighter in the way the action takes place. More elegant and smoother moving, plus the animation is much better. Having said that, this isn't the greatness of NG, but it isn't horrible. PoP:WW would probably be considered some of the best action in an adventure game if it wasn't for Ninja Gaiden. The graphics in Warrior Within are pretty good too. The only complaint I have is segments being too grey. It looks good for what it is, but the setting in the present seems dull. The colors when you go to the past are much more vibrant. At least what I have seen. The grey color of the present also sometimes makes it hard to see where to jump around in your surroundings.
The platforming sections have been pretty good. Some nice jumps that make you think. Again, in a way, Ninja Gaiden has also tarnished this aspect for me. Even something as simple as wall running you still have to hold onto the R trigger. In Gaiden all you need to do is run on the wall while moving and Ryu will automatically wall run. This leads to some cooler platforming segments in Ninja Gaiden as well where you run from wall to wall, building speed and then flipping up onto a higher platform. Not bad, but I had hoped for some simplification so you don't need to use as many buttons. I think Warrior Within makes you use more buttons than you should have too to do some platforming.
Couple other minor complaints:
1) What is with the prince grunting and screaming? I don't remember that from the demo. Here I am taking out some birds with my stick in the beginning and the Prince is going "ARRRRRH" "OHHHH". It caught me by surprise and I had to pause the game 'cause it made me laugh. Come on UBI.
2) Music. Nuff said
3) Some of the fighting aspects could still be refined. The battle system could be smarter. Maybe I need more practice, but sometimes when I get close to an enemy as I want to jump over him I accidentally springboard off of him backwards. And I have had a couple deaths where I spring board myself over a ledge!!!!

Secondly, with doing jumping attacks off walls the game shouldn't let you do them near a cliff. I did one near an edge and I hit the enemy and went flying off the ledge. It gets frustrating sometimes fighting in this game when stuff like that happens.
All in all, not a horrible game so far. Better than I thought it would be but it is just like I thought it would be in some aspects. Due to the increase in fighting abilities, I know I'll like this game better than PoP: SoT. But I don't think it will be a better game overall.