In the PS2 and Xbox versions, after completing "Friendship in Flames", one more mission "Revenge of the Sith", is unlocked. Both characters have nearly identical attack moves, and can gain access to special unlockable moves that can be unleashed when a "fury" or "focus" gauge is filled up during battle. The handheld versions of the game are played as a 2.5D side-scrolling beat 'em up game, where players can freely choose to play as either Obi-Wan or Anakin, traversing across roughly a dozen levels to battle a variety of enemies and occasionally dodge deadly hazards, such as a laser trap or a missile launcher.
The game features an experience system, whereby the player's character can upgrade attacks and gain new ones as they progress through the game. One feature of the game is called a Saber Lock - a sequence in which the player's character clashes swords with an opponent. Attacks can also be charged up for greater strength. These attacks can be mixed to create combination attacks. There are three basic attacks: fast attacks which do the least amount of damage, strong attacks which do more damage but are slower to execute, and the slowest but strongest critical attacks. Each of the playable characters (with the exception of the MagnaGuard) is equipped with at least one lightsaber. The game's combat system is heavily concentrated on lightsaber combat. There are 17 levels, interlaced with over 12 minutes of footage from the movie.
The player alternates between playing as Anakin Skywalker and Obi-Wan Kenobi, reliving various scenes from the film through the game's missions. It bares resemblance to 1999's Star Wars: Episode I: The Phantom Menace videogame where the overall game is the same as the actual film with a few minor changes in exposition and background information. The game was also released on the mobile phone and followed the storyline of all other versions. The DS version also features uses for its touch-screen capability. The other difference is that while the PS2 and Xbox versions feature a singular campaign, with player controlling Obi-Wan or Anakin depending on their scenes in the film, the GBA and NDS versions feature two separate campaigns for each one. The Game Boy Advance and Nintendo DS versions of Episode III are much the same to the console versions, except as a side-scrolling action game.
There are two different endings to the final battle, the first being that Obi-Wan defeats Anakin like in the film, the second being that Anakin kills Obi-Wan then meets the Emperor who gives him a new red lightsaber, Anakin in turn kills the Emperor and claims the new Empire for his own. The game ends with the duel on Mustafar between Darth Vader and Obi-Wan.
This includes Anakin's attack on the Jedi Temple, which culminates in a duel with Serra Keto, who happens to be the best student of Cin Drallig, who Darth Vader later fights and kills along with Keto. As Obi-Wan, much of the game is centered around destroying General Grievous, while the Anakin levels chronicle his fall to the dark side of the Force and extermination of the Jedi Order. It involves playing through the events as either Anakin Skywalker and Obi-Wan Kenobi, with radically different events taking place in either.
The game follows the movie storyline very closely, incorporating footage from the movie into the game and blending it well with the game portion itself. 7 Differences between the movie and game.