One of the best, longest and most challenging action games I've ever played.
The foremost impression that I was left with this game was that it is very hard, perhaps the most difficult game I have ever played. I began the game on the hard difficulty because I generally think games these days are too easy but when I hit the first boss and discovered her to be next to impossible, I set the game back to normal. Even at normal difficulty, the game is still very hard. The typical bad guys and monsters provide quite a challenge, but the bosses are unbelievable (there is somewhere around 7-8 in the game). With the exception of one of them, I could not defeat any of them in less than 15-20 attempts.
The difficulty of the game is a blessing and provides for an uncommon challenge. That said, there are times I did find myself annoyed by it but I did get used to it after a while. You are only permitted to save your game at specific save points throughout the game. Sometimes, you'll find that you wished the next point was a bit closer. There are a number of places where you repeatedly attempt to fight your way through a sequence of difficult battles only to discover after your hard-earned victory, that you have a whole set of traps and jumping puzzles to solve. If you fail, you have to start everything all over again.
The brightest point of this game, which is a hallmark of the entire POP series, is the incredible acrobatics and fighting skill of your character. This is what impressed me most about SOT and WW takes that to an even greater level. There are a large number of combos that you can activate by pressing various keys (how fast can you press Forward-Space-E-E-Mouse-Mouse-Mouse?). In SOT, I found myself become adept at a few key moves that I just used repeatedly throughout the game. In WW, you must learn the huge numbers of combinations or be destroyed. The difficulty of the game requires a great deal of player skill which is part of what makes this game so enjoyable. Taking a quick swipe at an enemy, doing a flip over the head with a slash to the back, followed by a back-flip to escape the enemy's attack is something to see. The addition of the ability to dual-wield weapons also adds complexity to the maneuvers.
The length of the game is also something of note. Action games tend to suffer from being too short. This is definitely the longest action game, by far, that I've ever played. The difficulty of the game contributes to this but also the shear size of the game. At one point in the game, you feel that the game should just about be over and then discover you've got quite a ways to go. The game also has a number of branches that you can freely move between including different areas of the palace as well as the ability to switch between the present and the past. You will find yourself occasionally wandering back and forth from various regions trying to figure out where to go to next.
The biggest thing I felt missing from WW that I enjoyed in SOT was the adventure and puzzle aspect of the game. In SOT, you frequently find yourself trapped in a room where you have to hunt for a way out or solve various sets of puzzles to open the way. WW has some puzzles and you have to keep your eye open for the exit, but everything is pretty straightforward and not terribly interesting in that respect.
The prince has special abilities similar to those found in SOT (slow time, reverse time, super attacks, etc.). You gain more abilities over time and additional "Sand Tanks" that allow you to perform more special actions. There's also the occasionally hidden room (which are fairly difficult to find) that gives you additional strength.
There's really not a whole lot to say about the graphics. They are quite good, but nothing really extraordinary and I would say they seemed on par with SOT but not something near the level of a Half-Life 2.
The sound is very good, especially the high-paced, heart-pounding music that kicks in at various points in the game. It can get slightly repetitive after a while, but that's to be expected when you play for quite a while.