Kingdom Hearts HD 2.5 ReMIX is an HD remaster compilation of the Kingdom Hearts series and follow-up to Kingdom Hearts HD 1.5 ReMIX. It includes full HD remasters of Kingdom Hearts II Final Mix and Kingdom Hearts Birth by Sleep Final Mix. It also includes a collection of cutscenes from Kingdom Hearts Re:coded and the credits accessible from the main menu contained cutscenes from Kingdom Hearts 3D: Dream Drop Distance.
This release marks the first time Kingdom Hearts II Final Mix and Kingdom Hearts Birth by Sleep Final Mix were made available outside of Japan. It was sold exclusively for the PlayStation 3 console, and sold along with Kingdom Hearts HD 1.5 ReMIX for the PlayStation 4, in a compilation titled Kingdom Hearts HD 1.5 + 2.5 ReMIX. It would be followed by the third and final HD ReMIX set, Kingdom Hearts HD 2.8 Final Chapter Prologue, which was released for PlayStation 4 in January 2017.
Changes to all three games include support for various video outputs (480p, 720p, 1080i, 1080p) and audio output supported in Dolby Digital 5.1 sound and DTS Digital Surround 5.1. There is now PlayStation 3 trophy support and an unlockable PlayStation 3 theme for each title. In addition, English dialogue to all cutscenes in Theater Mode are available in the Japanese release. Textures were updated, and the music was remastered.
Kingdom Hearts II Final Mix features remastered graphics and a completely re-orchestrated soundtrack. All cutscenes, including those that were created for the original Japanese version of the game, are voiced in English, with some of the audio originating from the English release of Kingdom Hearts 358/2 Days. The Absent Silhouettes and their respective Replica Data now use English grunts, laughs, and battle cries, while Roxas's have received more drastic changes to incorporate those of his Kingdom Hearts 358/2 Days incarnation, and even some of Ventus's from Kingdom Hearts Birth by Sleep. The sounds of Sephiroth's blade strikes have been replaced by those from Crisis Core: Final Fantasy VII. Due to a glitch in the game, Drive Forms now include a delay which halts game activity for one to several seconds while the game loads, unless the player pauses the game for a few seconds. This glitch was later fixed in the 1.5 + 2.5 ReMIX collection.
Kingdom Hearts Birth by Sleep Final Mix features HD graphics, and its controls were adjusted for the game's transition from the PlayStation Portable to the PlayStation 3. For instance, the camera can be controlled using the right analog stick, rather than the shoulder buttons. The various environments the player visits over the course of the game are more detailed in appearance, and new sound effects were added to these areas, as well. The Mirage Arena no longer has multiplayer capabilities; to compensate for this, the events and battles it hosts are more difficult, and additional challenges are featured, as well.
In the final cutscene in Terra's scenario, the Lingering Will sprouts a cape to maintain continuity between Kingdom Hearts Birth by Sleep Final Mix and its later appearance in Kingdom Hearts II Final Mix. While the entire soundtrack of Kingdom Hearts II Final Mix was re-orchestrated, the only pieces in Kingdom Hearts Birth by Sleep Final Mix that received any sort of changes were "Dismiss", "It's a Small World", and "Keyblade Graveyard Horizons". Additionally, Aqua's English voice actress Willa Holland provided new dialogue for the three cutscenes that are exclusive to Final Mix's Secret Episode.
Like with Kingdom Hearts II Final Mix, a glitch in the game causes a delay which halts game activity for one to several seconds when attempting to use any of the D-Links, unless the player pauses the game for a few seconds. This glitch was later fixed in the 1.5 + 2.5 ReMIX collection.
Kingdom Hearts Re:coded (HD Cinematic Story Videos)
Kingdom Hearts Re:coded was featured as over three hours of fully voiced, high definition cutscenes. In addition, it includes character reports. Unlike Kingdom Hearts 358/2 Days in Kingdom Hearts HD 1.5 ReMIX, Kingdom Hearts Re:coded features cutscenes from the Disney worlds, as well as battle scenes, and narration by Mickey. Cutscenes were added to better understand the Kingdom Hearts series, including one to connect to Kingdom Hearts χ. An additional secret ending, titled A Will that is Passed on, was added to connect to the events of Kingdom Hearts 3D: Dream Drop Distance. Additionally, due to Phil Snyder's retirement, Joe Ochman had to replace him as the voice of Jiminy Cricket, which included providing new dialogue for some of the new cutscenes, and redubbing all of Snyder's previous recordings.
In October 2013, Tetsuya Nomura said that Kingdom Hearts HD 2.5 ReMIX will contain more graphical improvements than Kingdom Hearts HD 1.5 ReMIX.
In a column with Tetsuya Nomura featured in Famitsu in March 2014, it was revealed that all recording for the game was finished.
- None of the actors who voiced characters in the Kingdom Hearts II Final Mix exclusive cutscenes were listed in the Kingdom Hearts II Final Mix credits.