The storyline will capture you like no other game has.
The combat system is somewhat unique, too. You're always on auto attack, but the damage is affected by different stats and "feats" your opponent has, and by your weapons damage and upgrades, which is an interesting addition, because that means that any weapon has the potential to be deadly depending on what upgrades you may or may not give it. The battles always keep the game interesting, but it isn't the combat that makes the game interesting.
The game is very much storyline driven. You have a certain about of "influence" over your allies based on how much they like and respect you, which is changed when you talk to them, perform certain deeds or favors for people, or even killing innocence. Influence affects how they fight and respond to you in conversation. You will find that, with enough influence, most of your allies can be turned into Jedi as well.
The story involves deceit and betrayal, emotionally attaching you to a story that you won't soon forget. The game requires you to make many decisions for yourself that affect the storyline greatly. The story is completely different if you take a Jedi's path over a Sith's path or vise-versa, and the story line on either side takes a good 30-40+ hours to complete, and even longer if you complete all of the extra tasks you are given on each planet you visit. KOTOR's faults, however, lie in graphical carelessness. The graphics aren't bad, but certain things could have been done much better. For example, the hundreds of hours of voice acting isn't done justice by the pathetic attempt at syncing the lips with the words. It looks totally fake, and looks like they could have tried a lot harder to make it look real. Beyond that, character models' actions often look a little screwy. For an example whenever someone uses a computer or are in the cockpit controlling a ship, their hands are never on the keyboard or controls, they seem to be either hovering or way off in the air to the left or right, and they just seem to be moving randomly. Considering the capabilities of the Xbox, it's pretty dissapointing.
but still, Star Wars Knights Of The Old Republic II is an incredibly enjoyable and, if you're lucky, emotional experience that you will never forget. The cinematic aspects of it are so well done that you become strongly connected with the story by the end, especially if you're a long time fan of Star Wars or RPGs in general.