Gameplay is similar to that of Asphalt 7: Heat, with the player given four control options; "Tilt to steer" (auto-acceleration with movement controlled by tilting the device), "Tilt and icons" (manual acceleration via an on-screen icon, with movement controlled by tilting the device), "On-screen controls" (auto-acceleration with movement controlled by an on-screen virtual steering-wheel), "Tap to steer" (auto-acceleration, with movement controlled by touching the side of the screen), and a traditional WASD keyboard scheme for Windows 8 devices. The five star rating system for each race, the use of primary and secondary objectives introduced in Asphalt 6: Adrenaline and also used in Asphalt 7 have all been retained in Asphalt 8. Three stars are awarded for finishing in first place, two for second, and one for third. Achieving secondary objectives, such as performing a given number of stunts or knocking down opponents, awards the player with two additional stars. Obtaining stars in an event is cumulative - players who finished first in an event without completing the secondary objectives may replay the race and obtain a five-star rating even if the primary objectives aren't met. The core gameplay is slightly different, however. As the subtitle implies, the focus of Airborne is on jumping, with tracks featuring a lot more ramps than in previous games.[5] As well as performing standard jumps, the player can also perform flat spins (by drifting onto a ramp) and barrel rolls (by hitting curved ramps).[6] All jumps earn nitro boost; the longer the airtime, the more boost earned. If you can crash into cars, light poles, and other things and destroy them you can also earn boost. Another new feature, which substitutes the "Adrenaline mode" in Asphalt 6 and 7, is the ability to perform a "Perfect Nitro". When the player hits boost, a small red zone appears in the boost bar. If the player hits boost again when the boost meter is in the red zone, the car will accelerate even more, with the boost lasting until the player runs out of boost, brakes, crashes or hits a ramp. In the initial version of the game, the career mode consisted of 180 events split into eight "seasons", which become progressively more difficult.[7][8] In later versions, additional challenges were added to the seasons. When the game begins, only Season One is available. Later seasons must be unlocked either by earning a certain amount of stars or by purchasing a "Season Unlock" in the in-app store.[9] The Great Wall update added 30 new events centered on the Great Wall.[10] The Dubai update introduced a new season where only fully upgraded cars are eligible to participate, besides adding three new events centered on Dubai.[citation needed] The San Diego Harbor update introduced a new season featuring events where the player can participate in a twenty-four car race (only on iOS 8), alongside several new events centered on both Dubai and the San Diego Harbor.[citation needed] Online multiplayer mode can be played both locally via Wi-Fi, and globally via the internet. There is also a "World Series" online multiplayer mode, although this mode is unavailable on iPod touch 4th generation and iPhone 4.[11] Playing on multiplayer is the only way to increase a player's in-game level, to which more credits are awarded as the player levels up. Asphalt 8 is the first game in the Asphalt series to use Game Center for achievements rather than Gameloft's own Gameloft Live.[12] The April 2015 update added support for the Apple Watch and it's compatible only on the iPhone 5 or later models using iOS 8.2 or later through the use of Bluetooth or Wi-Fi. Cars[edit] Besides the use of stunt jumps as a central gameplay mechanic, Asphalt 8 also makes extensive use of simulated HDR rendering and pixel shaders, as seen on the sky and specular reflections on the road surface. There are 111 licensed cars available in the game, divided into five classes, and their performance is now determined by the new Rank rating. The player starts with one car in the lowest class (Class D), the Dodge Dart GT (Starting Rank 505; Max Rank 778; Max Pro Rank 802). Unlike in previous games, all other cars are immediately available for purchase without the need to collect stars to unlock them. These include: in Class D, the Cadillac ATS, the Scion FR-S, and the BMW M3; in Class C, the Chevrolet Camaro GS, the Lamborghini Urus, and the Lotus Exige S Roadster; in Class B, the DS Survolt, the Aston Martin V12 Zagato, and the Ferrari 458 Italia; in Class A, the Marussia B2, the McLaren 12C Spider, and the Pagani Zonda R; and in Class S, the GTA Spano, the Ruf CTR3, and the Bugatti 16.4 Grand Sport Vitesse. The car with the highest Rank is the McLaren P1 GTR (Class S; Starting Rank 1588; Max Rank 1716; Max Pro Rank 1801).