Short answers, pulled from the story.
Final Fantasy XV was released for PlayStation 4 and Xbox One in November 2016, for Windows on the 6th of March 2018, and as a launch title for Stadia on the 19th of November 2019. A mobile version called Final Fantasy XV: Pocket Edition released in February 2018 for iOS and Android.
Final Fantasy XV began development in 2006 as a PlayStation 3 spin-off called Final Fantasy Versus XIII, making its total development span roughly ten years before its 2016 release. The project was only 20-25% complete when it was rebranded as a mainline entry in 2012.
Final Fantasy XV had sold ten million units worldwide across all versions by May 2022, making it one of the best-selling Final Fantasy games of all time. Within the first twenty-four hours of release, Square Enix reported five million units shipped in physical and digital sales combined.
Hajime Tabata directed Final Fantasy XV following a 2012 rebrand. Tetsuya Nomura was the original director of the project when it was known as Final Fantasy Versus XIII, and served as a co-director with Tabata until late 2013.
The Final Fantasy XV Universe is a multimedia project created by Square Enix to expand the game's narrative, first revealed at the "Uncovered: Final Fantasy XV" press event in March 2016. It includes the feature film Kingsglaive: Final Fantasy XV, the anime series Brotherhood: Final Fantasy XV produced by A-1 Pictures, several spin-off games, and downloadable content episodes released between 2017 and 2019.
Japanese gaming magazine Famitsu gave both the PlayStation 4 and Xbox One versions of Final Fantasy XV a score of 38 out of 40. The game also won awards including "Game of the Year" from RPG Site and RPGFan, and "Best RPG (People's Choice)" from IGN.