While Vice City is definitely much, much larger than GTA3 it doesn't really feel that much more different than GTA3. First of all, the city is much larger and there is more of everything. More cars, more missions, more sub-missions, more ticks (with cars and bikes) and more weapons. There is also more variety in missions and also, Rockstar has put in bikes! While the additions are great and all, the overall game's fundamental gameplay layout is the same. Too many missions feel similar, the AI still sucks, Tommy never learned to swim, and the targeting system is flawed. But the game is still very, very fun and open. The replay value is higher than the previous installment so this game is definitely worth the full purchase price.
The graphics remain very similar to those of the last game. It's a little bit smoother but overall, everything looks too rough and there is a lack of detail. But there is so much of… everything! The huge city, large number of people and many vehicles makes the game look like an actual, living city.
The game sounds very nice. The quality of the sound is great. The voice acting sounds just right for each character. The music is plentiful and there is a wide variety of genres available. But you'll still end up hearing a lot of repeats since you'll spend a lot of time in cars.
Final words: Though it doesn't offer many new things, it's still a long-lasting and very fun to play sequel.