The other title, Kingdom Hearts 0.2: Birth by Sleep – A Fragmentary Passage,[c] is an original game that takes place after the events of Dream Drop Distance.

To avoid having too much backstory in Kingdom Hearts III, series director Tetsuya Nomura chose to place this story he long desired to tell in this collection.

Some also praised the role of the collection in filling story gaps in the very complicated storyline of the Kingdom Hearts series.

[5] This collection features a high definition remaster of Dream Drop Distance, which Nomura stated was a full remake of the game since the original utilized the two screens of the Nintendo 3DS.

[6][13] The story begins after Kingdom Hearts: Dream Drop Distance when King Mickey reveals that he has secrets to confess relating to Aqua and her time in the Realm of Darkness.

[7][8][14] In terms of gameplay, the “Doubleflight” ability returns, which allows Aqua to leap higher and do a mid-air double jump, while also gaining a burst of speed mid-jump.

[18] In October 2014, when asked about the content seen in the secret ending, Kingdom Hearts series director Tetsuya Nomura stated, “It shows the existence of Aqua’s story in the Realm of Darkness.

[20] In September 2015, Square Enix announced Kingdom Hearts HD 2.8 Final Chapter Prologue, for release in 2016 on the PlayStation 4.

[6] Nomura stated that Square Enix developed the collection alongside the game Kingdom Hearts III.

They made the collection so players could experience some of the new gameplay elements being developed for Kingdom Hearts III "sooner than later".

[7][8] Nomura explained the game compilations title, stating that Kingdom Hearts: Dream Drop Distance is considered number 2.6 in the series since it follows the events in HD 2.5 Remix.

The Kingdom Hearts χ games are considered 0 in Nomuras counting system because the series protagonist Sora does not appear.

[42] Reviewers universally praised the graphical re-creation of Kingdom Hearts: Dream Drop Distance on the PlayStation 4 from its origins on the Nintendo 3DS.

[41] GamesRadar's Anthony John Agnello concurred, said that "Kingdom Hearts HD 2.8: Final Chapter Prologue is essential for the faithful, flummoxing for newcomers, and a promising start to the series' life on PS4".

[36] Some reviewers such as Push Square did find things to praise about the collection such as getting the chance to explore resolutions to the many cliffhangers left by the previous Kingdom Hearts games.

[45] The Independent praised the gameplay of An Fragmentary Passage as "gorgeous" and called Aqua's journey through the Hall of Magic Mirrors "devilishly fun".

[46] GameSpot also praised the compilation's inclusion of new stories, and Game Informer called the titles "good preparation for what's ahead".