Grand Theft Auto: Vice City took the formula from Grand Theft Auto 3, added a new city and setting (the 80's), new missions, and bam, you have an all new game. Though most of it is rehash, none of it is boring.
Graphics: The graphics have improved since GTA3, however, that doesn't really say much. The game is still not "realistic" looking, but nonetheless, the game looks great. My only complaint is in the lighting department. There are some instances when you are driving and the sun is beaming in your face. It makes it really hard to see where you are going and/or what you are doing. But other than that, the new city and setting are awesome.
Gameplay: Pretty much the same, just different story. Plus, another thing that is really amazing about this game over 3 is that every single mission is different. Whereas in GTA3, you would have like 4 or 5 driving missions, VC has that many, they just all involve different elements and always have some twist to them. That really makes the gameplay shine more in VC than 3.
Sound: All I have to say about the sound is that it is amazing. It's all 80's music. Who doesn't love that?
Replay: As last time with GTA3, you will be playing this game over and over again. Enjoy it.
Overall: Although the same gameplay to the core, this game is a great addition, and a must own if you ask me, for any PS2 owner's library. Get this game. You will put hundreds of hours into the game.