Kingdom Hearts' next mainline entry is likely to follow in its predecessors' footsteps through the inclusion of fantastical worlds, drawing both from Disney proprieties and original environments. Though there is still much to glean about the directions that Kingdom Hearts 4 might take in this regard, one feature from the series' past could provide a welcome addition to its new landscapes.
Kingdom Hearts 3D: Dream Drop Distance's oscillation between its protagonists Sora and Riku allowed the game to make proper use of its core conceit: the introduction of alternate worlds. As the two characters work towards Kingdom Hearts' Mark of Mastery exams, they encounter similar but different versions of both Disney and original environments; this is made apparent from the get-go through their travels into Traverse Town, where Sora and Riku run into separate members of The World Ends With You's cast. Though one TWEWY character, Joshua, is able to communicate between these realities, he explains that the two heroes don't share the same luxury, a feature indicative of the title's resulting narrative and gameplay.
Kingdom Hearts 4 Could Bring Back Dream Drop Distance's Use of Alternate Worlds
The use of alternate worlds in Dream Drop Distance was clever for a number of reasons. For starters, the game could rely on reusing environmental assets and similar level structures across the two protagonists while keeping its gameplay fresh by swapping between Sora and Riku's Command Decks and subsequent combat styles. This was also conducive for differing the narratives between the two, allowing the game to show a broader range of interactions with respect to the supporting characters of its environments. In turn, this made proper use of its changing perspectives while helping from a screen time standpoint, especially when having to contend with larger casts like the TWEWY crew.
Given the pattern set by Kingdom Hearts 3, KH4 will likely be vaster than ever before, featuring a number of emerging worlds from Disney's newer IPs as well as a few series-based locations. The small glimpse fans received from the game's announcement trailer seems to suggest that the idea of 'afterworlds' will be present throughout Sora's journey given his fate from the previous title, which might be applicable across more than Kingdom Hearts 4's Quadratum. With Sora and his friends being separated for an amount of time, Kingdom Hearts 4 could play off Dream Drop Distance's conceit, having it so that Donald, Goofy, and the like could be just out of reach from reuniting with Sora by way of alternate realities.
If Kingdom Hearts 4 were to follow this formula, the options could be vast in the title's design and narrative approaches. The idea of alternate worlds could tie into their overall aesthetic; for example, if Sora's Quadratum is a more realistic look at Shibuya, the version of it that Donald and Goofy traverse could be closer to its more stylized depiction in The World Ends With You. Alternatively, KH4 could follow Dream Drop Distance's heightened focus on different narratives across the same IPs, which would be incredibly useful in the wake of new Disney worlds to explore. A potential Kingdom Hearts world based on Star Wars, for example, could have Sora face-to-face with the property's villains while Donald and Goofy make allies with its heroes, as the two groups work to bridge the gap between their realities.
Lastly, given Kingdom Hearts 4's focus on Strelitzia and Sora, the use of alternate worlds could emphasize the notion of separate realities for the living and the dead. This could be handled in such a way where Sora's journey across Disney worlds has him interacting with characters who have passed away in their stories, like Big Hero 6's Tadashi, while Donald and Goofy are instead in the worlds of the living. Such a design choice could play into fans' guesses that Donald and Goofy are meeting Hades, the God of the Underworld, in search of their friend during the game's teaser trailer.
Kingdom Hearts 4 is currently in development.