Mortal Kombat X[b] is a 2015 fighting game developed by NetherRealm Studios and published by Warner Bros. Interactive Entertainment for PlayStation 4, Windows, and Xbox One. Versions for the PlayStation 3 and Xbox 360 were also due to release, but both versions were cancelled. It is the tenth main installment in the Mortal Kombat series and a sequel to Mortal Kombat (2011), taking place 25 years later after the events of its predecessor. High Voltage Software developed the Windows version of the game, with Polish studio QLOC taking over the work on it shortly after the release of Kombat Pack 1. Like previous Mortal Kombat games, Mortal Kombat X's gameplay consists of two players, or one player and the CPU, fighting against each other with their selected character, using a large, varied array of character-specific attacks. The game contains several modes, such as a story mode, which mainly takes place twenty-five years after the previous Mortal Kombat game, several 'Tower' modes, which feature dynamically changing challenges, numerous online modes, and the 'Krypt', a mode played in a first person perspective, where players explore the areas unlocking a variety of in-game items. The console versions of Mortal Kombat X received critical acclaim upon release. Most praise was directed at the game's controls, overall gameplay, graphics, story, and characters, with some reviewers calling it the best game in the Mortal Kombat series. However, the PC version of the game was met with mixed reception, with reviewers citing numerous technical issues (including frequent crashes and slow netcode) as problems that severely hinder the experience. Selling more than 10 million copies, the game was the fastest-selling game in the franchise and the ninth best-selling retail game of 2015 in United States.[3] An upgraded version of Mortal Kombat X, titled Mortal Kombat XL,[c] was released on March 1, 2016, for PlayStation 4 and Xbox One, including all downloadable content characters from the two released Kombat Packs, almost all bonus alternate costumes available at the time of release, improved gameplay, and improved netcode. This edition was also released for Windows on October 4, 2016. A sequel, Mortal Kombat 11, was released on April 23, 2019, for Nintendo Switch, PlayStation 4, Windows, and Xbox One, with another follow-up released on September 19, 2023.