The PS4 versions of the classic Kingdom Hearts games have improved load times when compared to the previous PS3 versions. In addition the slow lag time of activating Drive Forms in Kingdom Hearts II Final Mix or D-Links in Kingdom Hearts: Birth by Sleep Final Mix (unless if the player paused the game for a few seconds) have been fixed which was one of the glitches that Kingdom Hearts HD 2.5 had.
As of June 12, 2017 two new DLC was added to the Playstation Store. While one of these is an extended cutscene for 358/2 Days, the other is a Theater Mode for Kingdom Hearts Final Mix. Notably this version, along it's original version and the original version of Kingdom Hearts II did not have a Theater Mode to replay any voiced cutscenes that were throughout the game from the main menu.
Originally this title was used by Square Enix as the name of a two disc collectors special on the PS3 that was only sold on their official Kingdom Hearts website. However this 2017 release for the Playstation 4 is completely unrelated to the collector's set and is instead released on a single disc.
Much like with Kingdom Hearts HD 2.8 Final Chapter Prologue (2017), this title was released on the franchise's 15th Anniversary. However only this game is being advertised as the 15th Anniversary release, especially since 2.8 was originally intended as a 2016 release. Additionally this games' release in Japan is nearly two months after 2.8's release.
Much like with Kingdom Hearts HD. 2.8 Final Chapter Prologue, the Playstation 4 releases of Kingdom Hearts HD 1.5 Remix (2013) and Kingdom Hearts HD 2.5 Remix (2014) will also run at 60fps (frames per second). This is the only main change to these games compared to the original PS3 releases.