Mafia II

Not missable, at the end of game.

Finish chapter 15
....

You'll be aided bt Joe during this final battle. Since the room is a full circle, you need to move to the outter ring to have any hope of finding cover.

The small control booths are a great place to set up camp. You can guard one side, and joe will cover the other, allowing you to easily take out Falcone's guards.

When all of the cronies are dead, Falcone will pop up from the center with a toting machine gun. There is no need to move from your location, just headshot the mob boss to take him down. With your target killed, you'll have completed all of Mafia 2.

Source: http://www.gamespot.com/features/6274410/p-16.html