GTA clone, but so much more...
After you get your mansion back from the police and you renovate it, then you can start upgrading it, buying new furniture and decorations etc.
You can also hire henchmen to do your dirty work for you, a driver, a guns dealer, an assasin etc. You can even go further and take controll of each of these for the jobs Tony wouldn`t really fit doing. You can call you driver to deliver your car wherever in Miami you are, this also saves you from having to steal a car every time you need to go someplace (one of my biggest frustrations with gta). You can buy better and better cars and, unlike GTA, you get to keep then and have them delivered whenever you need them.
The streets of Miami are quite detailed with all kinds of shops and alleyways where you can do all sorts of "business".
The variety of cars is pretty big, specially the cars you can buy, there are plenty to chose from, from a pimp mobile ( :P ) to a streach limo, even 4x4s are avalible for you to buy.
There is a lot of stuff that sets this game apart from GTA, and it is a much better game than The Godfather (by EA), but i won`t tell you any more of the features, all i can say is this game is deffinetly worth buying.
I`d reccomend this game to anybody who enjoyed playing GTA: Vice City, even though it`s not as good as San Andreas, to my mind, it comes second surpassing many overbudgeted and overhyped games.