One word: Astonishing
What captures me the most is the storyline which gives me the feeling of "what's coming next?" Everything is so well connected, the right items at the right moment, the bosses, the new zones you can go, it is just incredible how well this game was made.
The graphics are good, I love the soundtracks, they are played perfectly according to where you are and the situation, and the game play is just addictive.
Today, I decided to start playing again!!! yes, after more than a decade... I just love it.