For those that played mafia....
 

Can you tell me how it end after the part where I finally kill that one guy after screwing up 4 times (with the restuarante, the car, jammed gun, and the train)

I don't remember anything specific about the plot, but I seem to remember at the end you and your buddy kill somebody important then you fight it out with each other at some museum or something.

Your character rats everybody out and gets out of the Mafia scene. Then they show him as an old man watering the lawn or something. A fancy car drives up and some guys get out bringing a message from the boss, a shotgun round to the face. You die, the end, morals and blah blah blah etc.

I heard in the begining Saleri or what ever his name was tried to double cross you.