The game was announced in September 2013, at the Game Developers Conference in San Francisco, and was initially intended for release in Holiday 2014. In January 2014, the game was delayed to May 29, 2015. On April 8, 2015, the developers announced that the game would release on October 16, 2015, for Windows, Xbox One, and PlayStation 4. The game's box art, soundtrack and animation choices were based on Turkish culture. During the game's development, Eidos-Montreal worked closely with Square Enix's Tokyo studio to design the game's spin-off, the survival horror video game, Tomb Raider: Definitive Edition.
The game proved commercially successful; at the time of its release Microsoft said that it has shipped over five million copies of the game, and by August 2016 Square Enix reported that it had shipped over 2.1 million copies as of August 2016, with total sales of over 3.7 million copies of the game by August 2016. The game has sold over 6.5 million copies as of May 2016. Tombs containing the game's secrets are notoriously difficult, prompting players to find other methods of progressing in the game. Because of its difficulty, the game has been described as the "most challenging Tomb Raider adventure yet". In November 2015, the game was nominated for twelve awards, including Console Game of the Year and Game of the Year; these nominations were based on sales data collected between November 10, 2015 and July 31, 2016. The game's sales led Square Enix to rethink the company's entire approach to producing games; while they had previously released a full-scale sequel every five years, they now only have the new volume every four years, with the next new volume coming in late 2019. The release of the game was the culmination of Square Enix's new approach to game development; it used the game to help test how popular the company's approach to game development was.
Figure 13 depicts how changing the AGTS values affects (1) the percentages of the numbers of eye fixations that fall within AOIs (PNFIA) shown in grey and (2) the percentages of the durations of the eye fixations that fall within AOIs (PDFIA) shown in black. The plots show the mean and standard error associated with every AGTS value. In addition, the fitted polynomial equations and the R2 values are provided. d2c66b5586