I've played for about five hours so far.
First off, GTA:VC is more an evolution than a revolution. It's a more polished, hipper, funnier version of GTA3. And I'm enjoying it plenty!
The writing and dialog is great. It's coarse, even brutal at times, but darkly humorous. I've laughed out loud several times.
Favorite quote to this point is from the chick you meet on the boat (turns out she's a stripper): "Mind if I rest my hand in your lap?"
Vice City plays much like its prequel, with several improvements and important differences. For example, targeting is easier than before. You can now ride motorcycles (which sound awesome). And - very cool this is - you can now jump out of a moving vehicle!
The missions start off slowly, but they're starting to heat up. More cutscenes than the original are helping to form the story.
The atmosphere is great. I cannot stress enough how much these authentic 80s tunes add to the game. They really help bring the game world to life. Besides the great tunes on the soundtrack discs, I've also heard Loverboy, Animotion, Quiet Riot, and The Cult. Sweet!
The environs are authentic, with bikini-clad rollerskaters at the beach and Hawaiian-shirted guys everywhere.
Did I mention the voice acting? Phillip Michael Thomas (Tubbs in Miami Vice) voices your comrade, and that's just way too cool.
Graphically, the game seems only slightly improved over its predecessor. Meaning, the game looks very nice at times, and dated at others. The neon lights at night are a great, great touch, but the raindrop effects on the "camera" lens have been done much better by other games.
Character models are improved over the last game, as are the animations. These characters move just right - their gestures complement their dialog almost uncannily.
So far, a top-notch job by Rockstar. Can't wait to see more!
Kolgar