This game is very good as a sequel to its DOS-based predcessor, though it doesn't quite make it in other aspects.
One improved aspect of it are the graphics. No more limited color palette (this of course depends on your video card, but I'm sure it doesn't look as bad as the first did in any way), more smooth scrolling, and an automatically increased resolution which subtracts from the pixelation rate. What's improved as well is the sound quality. There are real sound effects and a bit of dialogue between the pedestrians walking down the streets and the player. There are also random radio stations (each lasts about 24 minutes, my evidence from digging this up from the game files. Please don't tell Rockstar North) you can enjoy hearing while committing random and organized crimes in a vehicle.
On the other hand, the gameplay haven't moved too far from its arcade-style gameplay and "go-this-do-that" missions. Whoever doesn't like arcade games, will certainly dislike this one. There's also a lack of storyline, something "Grand Theft Auto 2" could compromise on in comparison to its predecessor (and something that will be greatly compromised in "Grand Theft Auto 3" and further).
And today's lesson is: "Grand Theft Auto 2" could be better.