Take-Two Interactive Software is a large AAA publisher with two large development studios under its control. One of them, Rockstar Games, developers of GTA 5, release new games relatively rarely and seldom work on more than one project at a time.
The other, 2K is churning games out like crazy. 2K themselves have a few other studios under them, though most of them have been rebranded to be "2K insert city name here". Firaxis is among the best known to retain their name.
2K also happens to be the developer of the Mafia franchise. The Mafia games are set in an alternate version of the United States where locations are based on real cities but given fictitious names. The player controls a character from third-person view and is tasked with performing a number of criminal activities in an open world. Organised crime acts as one of the main themes of the story, there is an emphasis on vehicles and committing criminal acts will increase the player's wanted level, resulting in NPC police forces chasing them.
Now remove the first sentence of the previous paragraph and replace "Mafia" with "GTA" in the second. Notice anything? Yeah, the two franchises are a tad similar. Granted, currently GTA takes place in a modern setting, but over the course of the series, players have explored various eras and decades. The main thing that differentiated Mafia from Rockstar's somewhat more popular franchise was its centered focus on the Italian mob, hence the name.
GTA games have always hopped across the country, placing players into the shoes of all kinds of diverse characters. With the exception of Inuits and Native Americans, pretty much every major group has been represented as a playable character in story mode — not to forget there being no women protagonists of course, which is pretty sad if you think about it (though they are playable in GTA Online... and apparently don't get killed as much). Players took on the roles of street gangsters, immigrants, rich middle-aged white men who have fallen from grace, assistants, leaders of biker gangs, drug addicts and moderately high-ranking members of the dominant crime syndicate of a given region.
On the flipside, Mafia always gave players control of an Italian-American who gets involved with the mob reluctantly — and by "always" we mean "both times". So there was at least a clear thematic divide. Well, with Mafia III, that goes out the window, since you're playing as a biracial, part-African-American Vietnam war veteran who is also an orphan and is not affiliated with the Italian mob.
