Not as good as the Pc version.
First, the story is great, but it misses a few beats for me. The beginning, which takes place in the future of where you play, is okay, but is super boring. This is aided by really poor driving mechanics. When you are told to lose the gangsters in the first mission, your car takes forever to go from 0-30. Even though its a 30's game, its like your car has a one-stroke engine and no traction control. When I got hit and stopped, I died in every mission because the gangsters could just shoot me while my car was preparing to actually move. The gunplay is boring, and has no difference from GTA whatsoever.
The graphics- What the hell? I saw noticeable pop-up right next to my face. I might as well give a monkey a paintbrush and ask him to draw the graphics for a game- even those would be better than the ones on the 'box.
All in all, if you want to play Mafia, go for the pc version instead. Leave this port where it belongs- on the bottom of the bargain bin.