Moral and ethical dilemas, excellent game play, and a wonderful story.
This game is one of the best action RPGs of its generation. It is, without much debate, the best Star Wars game produced. I won't get into a review here as you can easily get those details from IGN.
However, it is very important to stress that the innovation the game presented was to have the story changed based upon the moral choices the player makes in game. Anyone that knows Star Wars knows the force has a light side and a dark side. This game allows your character to choose what side of the force you wish to represent. The choice isn't one big decision, but, like in life, decided by all the little actions and decisions you make along the way.
The opportunity for a parent to do some moral and ethical coaching over the course of the game is enormous. Quite simply the question shouldn't be whether or not to let your child play this if they wish, but if they should play it, how can you involve yourself in their experience. In many ways, it is an antithesis to Grand Theft Auto. In this game, good moral decisions come at a cost (typically material) while poor moral choices are broadly illustrated as wicked and self-serving. Unlike other games, you cannot hide from your malicious decisions.