The worlds featured within the Kingdom Hearts series are as much a draw of the games as Square Enix's action combat and winding narrative. However, looking at the history of the series, it is interesting to note how few unique worlds any one Kingdom Hearts title has that don't appear in another entry.
While the spin-off and side installments of Kingdom Hearts reuse worlds often, Melody of Memory will have to be left out since its role as a recap game means that it revisits every level from the series. With that stipulation, the list is initially impressive, until fans realize that the majority of these worlds were only recently introduced into the series.
Deep Jungle
The first of only two worlds to not be revisited from the first Kingdom Hearts, Deep Jungle takes Sora to the story of Disney's Tarzan. This world's removal from future titles is actually an interesting story on its own. Unlike any world that Square Enix just decided not to revisit, this world never returned because Disney's licensing rights for the Tarzan IP ran out after the first Kingdom Hearts appeared. So, this is likely one world that will never return for legal reasons.
End of the World
The final world of the original Kingdom Hearts is also the only world that the game has chosen not to return to. From a lore standpoint, however, there's at least a good reason for the world to have not appeared since being the location of the final battle against Ansem/Xehanort. That would be the fact that the End of the World was a temporary place where worlds destroyed by the Heartless gathered and were released again after beating the game.
Land of Dragons
Similar to the original title, Kingdom Hearts 2 also boasts only a few worlds that have remained unique in the history of the series. The Mulan-inspired Land of Dragons stands as an impressive use of the original movie's beautiful set pieces to make for incredible locations to fight against hundreds of heartless and some stellar bosses. It makes for a unique experience that might be best left as it is without overusing the impressive world.
Timeless River
The Timeless River was easily one of the biggest selling points for Kingdom Hearts 2, as it promised to bring classic Disney cartoons to the mid 2000s. While the idea was novel back when the game first launched, it would certainly be welcome for a return trip with the new visuals available from Kingdom Hearts 4's engine. Another return to the black and white, rubber hose era of Disney would be a great addition to the next game.
Pride Lands
The Lion King-inspired Pride Lands stands out among Kingdom Hearts 2 levels, as well as against the rest of the series as a whole. This is due to the way that Donald's transmog magic transforms Sora into a lion and lets Goofy spin-to-win so that the group can blend in with the African wilderness. For longtime fans of the series, this level also acts as a small nod to an older design for Sora where he was an anthropomorphic lion-boy with a chainsaw.
Disney Town
When Birth by Sleep first launched, it actually introduced a number of worlds that were unique among the series. Now, Disney Town stands as one of few areas to only appear in this one title thanks to Kingdom Hearts Union X revisiting so many series locations. Even so, Disney Town is a fun little side adventure for Ventus, Aqua, and Terra to visit for a series of mini-games.
Deep Space
Stitch has made a few appearances in the Kingdom Hearts series at this point, but the character has only been given one chance to excel in his own world. Given that this left out some of Lilo & Stitch's fan favorite characters, a trip to Hawaii might be a good pick for a future game. For now, Stitch's Deep Space level acts as a great example of an interstellar world if Square Enix ever wants to dive into a Star Wars-themed world.
Daybreak Town
Coming from Kingdom Hearts Union X, Daybreak Town may be the most important world to future of the series during the Lost Masters Arc, outshining even the upcoming Quadratum. Technically, this world has appeared in more games in a way, but it hasn't actually been seen by any of the lead characters from Kingdom Hearts' Dark Seeker Saga. This is because Daybreak Town was flooded after the Keyblade War and the world of Scala ad Caelum has been built above it.
Game Central Station
Another world introduced in Kingdom Hearts Union X is Game Central Station, the Wreck-It Ralph inspired hub area that leads to a handful of other locales within the single level. This world will also be setting the stage for the future of the series as well, with Kingdom Hearts diving deeper into the concept of datascapes with each new entry. On top of the lore implications, Game Central Station is also home to one of the longest and most successful storylines in the mobile title.
Country of Musketeers
As the series moved to Dream Drop Distance, Square Enix toned down the amount of retreading that each game would spend time on. The result is levels like Country of Musketeers, which follows the 2004 film Mickey, Donald, Goofy: The Three Musketeers from both Sora and Riku's perspectives. This particular world is most notable due to the way that it fills in some of the time before Mickey becomes king of Disney Castle and gives another face-off against Pete.
La Cite Des Cloches
In several ways, La Cite Des Cloches could be seen as one of the most impressive worlds in the Kingdom Hearts series. This is due to the way that the world based on The Hunchback of Notre Dame fits when being filled with the colorful Dream Eaters that make up the enemies and companions in Dream Drop Distance. It's a unique case where the world vibes with the new concepts introduced by Square Enix.
Symphony of Sorcery
The Symphony of Sorcery is another strange world that dives into the memories of King Mickey and the Disney side of Kingdom Hearts' history. Again appearing in Dream Drop Distance, this world tasks Sora and Riku with following the magical music of Fantasia in order to save a sleeping King Mickey and fight the demonic Chernabog. It's an impressive world that makes the most out of the limited story available from its source material.
Toy Box
One of the first levels that players will explore in Kingdom Hearts 3, the Toy Box finally made good on rumors that have existed since the first game in the series. Not only does Toy Box allow Sora to finally team up with Woody and Buzz, but it also introduces Verum Rex and Yozora, which appear to have a larger role than originally implied. On top of the lore implications, the Angelic Angel boss fight is also one of the creepiest things Square Enix has ever produced.
Kingdom of Corona
Introducing the Kingdom of Corona into the series was a huge step for Kingdom Hearts 3. Having the cast of Tangled appear in a numbered title opened the door for the modern Disney era to have a presence in a series that had historically looked at classic titles. At the same time, the pacing of the world itself and the way that it does little to enhance the story with Sora's interventions makes the Kingdom of Corona one of Kingdom Hearts 3's lower points.
Monstropolis
One of the better levels in Kingdom Hearts 3, Monstropolis takes the world of Monster's Inc and gives Sora, Donald, and Goofy a part to play in an entirely new story. In several ways, it acts as a great nod to what might be happening in the Disney world after the events of the original movie, and has room for the Kingdom Hearts narrative to stand on its own. Additionally, this world gave fans one of the best Kingdom Hearts related memes, with the way that Mike and Sully ditch Vanitas through a nesting doll of transporting doors.
Arendelle
Easily the worst world in Kingdom Hearts 3, Arendelle does very little to improve on one of Disney's most successful franchises of all time. The story is a boring retelling of Frozen, with an environment that forces players to climb up a snowy mountain three times in a row. The only part of the world that really excels is the final boss fight against Skoll, and that is more for the spectacle than the actual combat design.
San Fransokyo
The final world to only appear once in the series comes again from Kingdom Hearts 3. Taking another risk to give the Big Hero Six level its own story, this world manages to excel by making Sora, Donald, and Goofy's inclusion feel necessary and impactful. The success of this world is another example of how Kingdom Hearts should focus on original stories within known worlds, instead of rehashing the movies that these locales are based on.
Kingdom Hearts: All-In-One Package is available now for PC, PS4, PS5, Switch, Xbox One, and Xbox Series X/S.