This collection gathers enhanced versions of several Kingdom Hearts titles, with a number of story additions and changes.
Kingdom Hearts II FINAL MIX adds new cutscenes drawn from the Kingdom Hearts II novels, several featuring Roxas — including scenes of him talking with Axel in Twilight Town in the Organization's black coat — plus added moments with Roxas and Riku (such as their second battle, where Riku takes the form of Ansem, Seeker of Darkness), Naminé leaving with Axel, Riku and Sora speaking before the 2nd Armored Xemnas fight, Xigbar and Zexion discussing Xemnas, and the Organization debating their plans and reacting to events like Axel's death. Zexion's weapon is also revealed: a large book called a "Lexicon" that traps enemies in an alternate reality.
Kingdom Hearts Birth by Sleep FINAL MIX makes smaller tweaks: in the final cutscene of Terra's scenario, the Lingering Will sprouts a cape to stay consistent with its later appearance in Kingdom Hearts II Final Mix. While Kingdom Hearts II Final Mix's soundtrack was fully re-orchestrated, Birth by Sleep Final Mix only changed the tracks "Dismiss," "It's a Small World," and "Keyblade Graveyard Horizons," and Aqua's English voice actress Willa Holland recorded new dialogue for the three cutscenes exclusive to the Secret Episode.
Kingdom Hearts Re:coded is presented as more than three hours of fully voiced HD cutscenes with character reports. Unlike 358/2 Days in the 1.5 ReMIX collection, it includes Disney-world cutscenes, battle scenes, and narration by Mickey, plus added scenes for better understanding the series — including one linking to Kingdom Hearts χ. A new secret ending, "A Will that is Passed on," connects to Kingdom Hearts 3D: Dream Drop Distance, and following Phil Snyder's retirement, Joe Ochman took over as the voice of Jiminy Cricket, recording new dialogue and redubbing Snyder's earlier lines. Finally, Kingdom Hearts 3D: Dream Drop Distance is experienced here as a set of cutscenes accessed through the credits menus.