In 2012, Square Enix announced Kingdom Hearts HD 1.5 Remix for Playstation 3. It contained only the first three games in the series and was released in 2013. Yet, immediately after 1.5 was announced, it was hinted that a second collection containing more games was soon to follow. After a year of hints and denials, Kingdom Hearts HD 2.5 Remix was officially announced at a Kingdom Hearts event at Disney's D23 Expo in Japan. It was released in 2014 and contained Kingdom Hearts II Final Mix, Birth by Sleep Final Mix & cutscenes from Re: Coded. This marks the first time Kingdom Hearts II Final Mix and Birth by Sleep Final Mix will be available outside of Japan.
During an interview with co-director Tai Yasue at E3 2014, he mentioned that the development team is made up of 70 people many of whom are also working on Kingdom Hearts III. He also that in order to focus on Kingdom Hearts III, the developers decided to drop the multiplayer aspect of the Mirage Arena in Birth by Sleep. They re-worked the Mirage Arena's bosses so that they would be easier playing solo, and that the Mirage Arena would have new rules and bonus.