As with the 2002 game, players control Tommy Angelo throughout the game's single-player campaign, and its world is navigated on foot or by vehicle. New to the remake is the introduction of motorcycles, a first in the series.
Mafia: Definitive Edition's gameplay mechanics are based on those of Mafia III. A 'Classic Difficulty' setting is also included, serving as the game's hardest difficulty setting that changes some gameplay mechanics such as ammunition management and police response to crimes, bringing the game closer to the original 2002 game.
Outside the main story mode, a separate Free Ride mode is included "as a nod to the original game", allowing the player to explore the city at their own leisure without any mandatory mission objectives.
Unlike the original game, however, Free Ride and Free Ride Extreme are merged into one game mode, with the latter's outlandish and over-the-top side missions incorporated into the main Free Ride segment as hidden secrets to be uncovered by the player.
A post-release update released in October 2020 added new activities in the game's Free Ride mode, including taxi missions and a racing mode which takes place in the autodrome featured in the mission "Fair Play".
Also included in the update is the ability to play the game in black and white, labeled in the game's settings menu as "Noir Mode" as a homage to film noir movies of the era, as well as various options allowing the player to show or hide parts of the game's HUD.
Plot
In 1930, during the Great Depression, impoverished taxi driver Thomas "Tommy" Angelo is strong-armed by two members of the Salieri crime family—Paulie Lombardo and Sam Trapani—into helping them escape an ambush by the rival Morello crime family.
Although he is offered a job and is compensated for his help, Tommy Angelo returns to his job the next day until two Morello family members attack him in an act of revenge. After Sam and Paulie save him, Tommy asks Don Ennio Salieri for help and exacts retribution upon his attackers, while agreeing to join Salieri's organization as an associate.
Assisting with the operations of Salieri's rackets across Lost Heaven, overseen by his consigliere Frank Colletti, he befriends Sam and Paulie during the jobs they perform together, while earning Salieri's respect by thwarting an attempt by the Morello family to take over one of his rackets.
In 1932, Tommy, now a made man, begins a relationship with Sarah Marino, the daughter of Salieri's bartender Luigi, after protecting her from some punks. Under Salieri's orders, Tommy and Paulie raid the gang's hideout in retaliation, but Salieri reprimands them for killing their leader, who was the son of corrupt city councilman Roberto Ghillotti.
Tommy is later ordered to bomb a brothel for switching its loyalties to Morello, and kill an informant working there, but spares her at Sam's request and lets her go in exchange for her silence. In 1933, Don Marcu Morello ramps up his efforts to dismantle Salieri's organization, and gains support from Ghillotti, who desires revenge for his son's murder.
When Frank disappears with the family's account books, Tommy finds him preparing to leave the country with his family, having made a secret deal with Morello and the FBI. Learning Morello threatened his family and sympathizing with Frank's disillusionment with the mob lifestyle, Tommy allows him to leave with his family for Italy in exchange for the books, later lying to Salieri that he killed them.
By 1935, with Prohibition over, both Mafia families begin moving out into new rackets, while Tommy, promoted to caporegime for his successes, marries Sarah and starts a family.
Upon learning Salieri is attempting to bribe law enforcement and city officials in his pocket, Morello attempts to assassinate him in a restaurant. Tommy protects him, and when it's revealed that Salieri's bodyguard has been spying on him for his rival, the families go to war.
Tommy is sent to publicly assassinate Ghillotti to send a message that Morello can't protect his friends, and kills Morello's brother and right-hand man Sergio. The war eventually concludes when Tommy, Sam, and Paulie kill Morello himself as he was attempting to fly out of the city, this being accomplished when Tommy shot down Morello's plane, and then executed the gravely injured Marcu Morello with a Thompson submachine gun.
By 1938, the Salieri family is in full control of the city's rackets. When Tommy, Sam, and Paulie are sent to retrieve a stash of diamonds hidden in cigar boxes seized by customs officers, they are shocked to find a hidden shipment of heroin instead; Salieri had warned his men against dealing hard drugs.
