Kingdom Hearts 0.2 Birth by Sleep -A fragmentary passage-

Kingdom Hearts 0.2 Birth by Sleep -A fragmentary passage- is the ninth game in the Kingdom Hearts series, released exclusively for the PlayStation 4 as a part of the Kingdom Hearts HD 2.8 Final Chapter Prologue collection.

The story acts simultaneously as an epilogue to Kingdom Hearts Birth by Sleep and a prelude to Kingdom Hearts III, and also shares a connection with Kingdom Hearts χ, chronicling the rest of Aqua's journey through the Realm of Darkness. The game utilizes, the same engine used for Kingdom Hearts III.

Story
In the aftermath of a spectacular battle in the Keyblade Graveyard, a hooded figure holding a Keyblade possessing an eye observes as Kingdom Hearts appears in the sky.

In the Mysterious Tower, Yen Sid informs Riku, Kairi, and King Mickey of their latest objective: to rescue Terra, Ventus, and Aqua from their fates. Mickey reveals a secret to Riku: right when they closed the Door to Darkness, Aqua was there with them, and tells his story.

Following her climactic battle with Terra-Xehanort that left her stranded in the Realm of Darkness, Aqua arrives in the remains of Castle of Dreams, where she discovers that time does not pass in the Realm of Darkness. As she traverses the ruins of Dwarf Woodlands and Enchanted Dominion, she encounters mirages of Terra and Ventus and battles a phantom of herself. She eventually catches up to Terra and Ventus in the remains of Enchanted Dominion. She briefly speaks with Terra, but he transforms into Terra-Xehanort, who demands to know if Ven is in the Chamber of Waking inside Castle Oblivion; Terra fights back and Aqua is pulled into darkness again, but is found by Mickey. After Mickey explains that ten years have passed in the outside world, she agrees to help him find a Keyblade of darkness in order to seal the Door to Darkness and learns that Sora and Riku, the two boys she encountered ten years earlier, have been helping to save the worlds. They locate the Keyblade and catch Riku just as Sora defeats Ansem in End of the World. Mickey and Aqua rush to aid Riku just as he is attacked by Heartless. Aqua sacrifices herself to keep them at bay and falls deeper into the darkness while Mickey and Riku seal the door with Sora. Trapped once again in the Realm of Darkness, Aqua vows to serve as a Wayfinder for anyone who will find themselves there in the future. Shortly afterwards, she witnesses the worlds being restored before finding Ansem the Wise at the Dark Margin.

Horrified by the news, Riku demands to know why Mickey kept this a secret from him. Yen Sid explains the dangers of venturing into the Realm of Darkness, something that Sora most likely would have tried to attempt, though they have now found a safer way. Yen Sid presents Riku and Mickey with new garments to protect them from the darkness for their journey to rescue Aqua, and assigns Kairi to train with Lea as a Keyblade wielder under Merlin. Shortly afterwards, Sora returns to the Tower, where Yen Sid explains that his task will now be to find a way to retrieve people's lost hearts. Though Sora has once again been stripped of most of his power, due to nearly becoming one of Master Xehanort's vessels, Yen Sid reminds him of a previous acquaintance who once lost and regained his power, and advises Sora to pay him a visit with Donald and Goofy.

Aboard the Gummi Ship, the trio ponder on how to travel between worlds due to the passageways having been sealed again. Remembering Yen Sid's words, "May our hearts be our guiding key", Goofy advises Sora to use his heart and he is able to open a passageway to Olympus Coliseum, setting the stage for Kingdom Hearts III.

Gameplay

 * Unlike previous games, Aqua starts at level 50.
 * The Command Menu is present, but excludes Summons.
 * Shotlock attacks return, with a similar Focus gauge.
 * Magic is present, using an MP gauge which functions like in Kingdom Hearts II. Only Firaga, Blizzaga, Thundaga, and Curaga are available. Additionally, picking up MP Balls can now help shorten the amount of time for MP Recharge to complete.
 * Magic now leaves an effect on the surrounding environment. For example, Blizzaga creates a sheet of ice to slide on.
 * Shortcuts have multiple "pages", scrolled via the D-pad separating Magic from Items.
 * "Situation Commands" are present.
 * Command Styles are present, activated through Situation Commands.
 * Flowmotion is available. However, Aqua can only do Rail Slide.
 * Aqua's appearance can be customized with different props or changing the color of her outfit. Completing Objectives is the primary method to unlocking more props.


 * Mickey is a party member in the game's final area, the Depths of Darkness.
 * Once unlocked, Teleportation can allow Aqua to revisit the areas that she has completed before through the use of Save Points.

Worlds
Playable
 * Dark World

Cutscenes
 * Mysterious Tower