"Prince of Persia: The Two Thrones is an action-adventure computer and video game developed and published by Ubisoft Montreal...
Following Warrior Within, The Two Thrones is the closing chapter in the The Sands of Time saga...
The Two Thrones combines exploration and combat. Both elements make use of the Prince's acrobatic capability and agility. Throughout much of the game, the player must attempt to traverse the palace by running across walls, ascending or descending chasms by jumping back and forth between walls, avoiding traps, climbing structures and jumping from platform to platform, making other types of well-timed leaps, solving puzzles, and using discovered objects to progress.
During combat, many of the same moves vital to the player in other situations can be put to use to overpower enemies. An example is the ability of the Prince to rebound off walls in order to strike enemies decisively. The player generally attacks enemies and blocks using a sword, although other objects/factors, such as the Dagger of Time and its time-control abilities eventually prove to be critical to victory.
In The Two Thrones, the Prince's acrobatic skills have improved. He is now able to launch himself off walls at 45 degree angles at strategically placed vertical shutters, slide down chutes, and balance on swinging poles, among other things. The designers have also improved the stealth system. Instead of merely being able to do more damage when striking without being seen, The Two Thrones uses a speed-kill system. If the player does not complete the speed kill, the enemy knocks him off and the speed kill fails. The amount of moves or the length of time required depends on how strong the opponents are. The same system is also used in some of the boss battles.
The Prince also develops a split personality, known as the Dark Prince, and this alter-ego constantly bickers with him in his mind about right and wrong. At times, the Prince physically transforms into the Dark Prince. These transformations are scripted and not controlled by the player. During these times, however, the Prince retains control of his body, and the player still has control over the character. For the most part, the Prince's dark side is simply an inner voice.
When controlling the Dark Prince, the player loses the ability to wield a secondary weapon, instead using the "Dagger tail", a bladed whip fused to his arm. This allows medium range combat moves and new interactions with the environment. The Dark Prince also constantly loses health as a result of the semi-transformation, with eventual death from the loss. He goes back to full health whenever he collects Sand, from either a monster or object. Also, his Dagger tail gives him a different button combination for speed kills, in which he strangles his victims. Coming into contact with water will allow the Prince to return to normal.
Source: Wikipedia, "Prince_of_Persia:_The_Two_Thrones," available under the CC-BY-SA License.