Kingdom Hearts 2 improves on the original in every way.
Graphics: The graphics were very good. The CG graphics in the beginning and in the end were amazing looked almost as real as final fantasy advent children. The graphics while playing and in the cutseens were very good.
Sound: I loved the music in this game.
The only thing i didn't like about this game was it was way too easy. If you like final fantasy games you'll love this game seeing FF characters in here was really cool. There are tons of extras to do like defeat the secret boss Sephiroth (extremely hard). Theres even a secret ending you can unlock by doing these things. Overall this game is simply amazing and its a definite buy.