The Godfather (in the film and novel) built a network and gave orders. All you get to do is take down NYC by yourself.
When did Don Corleone ever have to take over an enemy hub all by himself? According to the novel and films the only time he acted alone was when he decided his path of crime and violence by murdering Fanucci, which is a decidedly one-on-one affair. He never waltzed into the Barzini complex and took down the entire operation. This representation of "The Godfather" IP is painfully inaccurate.
Where is the mafia in the gameplay?
Where are Tessio's and Clemenza's armies?
Where is the Sicilian subtlety in doing favors and taking care of the neighborhood?
Where is omerta?
Where is the political maneuvering?
The answer to all of these: Not in this game.
This game should be called The One-Man Gun instead of The Godfather. Do yourself a favor and read Puzo's novel instead of playing this game.