The game's structure is basically the same from previous installments of the series.
Here are some things added to the game which weren't in its antecessor GTA V.
Co-op: Now you can invite any of your PSN®/Xbox Lives friends to join you in Quick Heists, missions or even mess around.
Decisions: Missions are very straightforward. The boss says what you have to do, and you do your own way. Decision situations are more common now and the way you behave affect the way your friends or bosses treat you and the entire structure of the storyline.
Friends: Back from GTA IV youll make friends are can engage in various activities with them.
Cheats: The game features the same system from Grand Theft Auto IV. Your cheats are saved on your phone. After completing some missions you gain access to Super Power Cheats, including Super punch, invisibility, flying, super speed and fire rockets.
Girlfriends: You can find love interests all over the map, like in San Andreas. Youll get girls numbers after dancing at a club like in The Ballad of Gay Tony. Youll find all these by simply visiting Love-meet.net.
Physics: The physics are returning from Grand Theft Auto IV.
Animals: Dolphins, Dogs, Alligators, Turtles, Sharks, Deer, crocodiles and snakes. Lions which escaped the circus can be found too.
Graphics: GTA VI uses advanced graphics proportioned by the eighth generation consoles.
Driving: The driving mechanics of GTA IV are making a return. Now there is an additional camera mode featuring the cockpit view of all vehicles. (Is possible to play the game in First person)
Quick heists: Quickly engage in a heist by using your phone. PSN® or XBL friends can be invited.
Combat: Shooting mechanics from GTA IV are returning. Now you can climb and shoot while hanging like in Uncharted. The fight system is a mix between IVs and that of Vice City Stories.
Stealth is now effective and is used in several missions.
Wanted Level search radius from GTA IV is returning. Upon beating the game players earn a police badge. Showing the badge when pursued by cops will erase your wanted level up to 2 stars.
Radio: Now is possible to play user tracks via Independence FM and even arrange the playlist. Other radios music can be added to the playlist.
Criminal activities: Assassinations and Car Thefts from IV; Empire building from Vice City Stories; Pimping and Burglary from San Andreas; Drug Dealing from Chinatown Wars and Robberies from V(all stores can be robbed now) are making a return.
Entertainment: Go to Comedy Clubs, Theatres, Strip clubs, Cinemas, Illegal casinos and even a circus, to have an off-mission fun. There are also diverse sport activities.
Eating: Fast food is accessible again and like in San Andreas you can become fat.
Car customization is more advance now, featuring a copy of Need for Speed Carbon's Autosculpt.
Below is a list of vehicles with links to GTA Wikia's correspondent page.
Not anything original. More of a selection from previous games.
Supercars and Sport Cars
Two-Doors and Hatchbacks
and Station Wagons
SUVs/Crossovers, Pick-ups and Vans