Despite both Sora and Riku being the two playable characters, Nomura emphasized that Rikus is the main focus of the game as it shows the character's growth across the series.

The Grid was originally intended to be playable only for Riku, while Sora would visit Space Paranoids. Nomura instead scrapped this idea and had both Sora and Riku visit The Grid.

Originally, elements based on Fantasia 2000 were to be included in Symphony of Sorcery, in which Riku would go to those parts, and Sora in the original Fantasia, however, Nomura found that they "had enough to work with" with the original Fantasia.

Celebrates the 10 Year anniversary of the Kingdom Hearts franchise. In addition references to all the previous main titles for the series are included in the game.

This is the final game that Chikao Ohtsuka and Leonard Nimoy voices Master Xehanort, as well Phil Snyder as the voice of Jiminy Cricket. This is due to the fact that Ohtsuka and Nimoy have passed away and Snyder has retired from mainstream voice acting in 2014. Incidentally all three of these actors only got to perform these roles twice (although Ohtsuka voiced Captain Hook in Kingdom Hearts (2002) as well).

When Young Xehanort takes Sora through a simulation of Traverse Town, he references the town's role in the entire series and Sora's journey's throughout it. This consists of Sora's first journey (Kingdom Hearts (2002)), Sora's journey through his memories (Kingdom Hearts: Chain of Memories (2004)/Kingdom Hearts Re: Chain of Memories (2007)), Sora's journey through the datascape (Kingdom Hearts Re: coded (2010)) and Sora's journey through his dreams (Dream Drop Distance).

According to Nomura, the reason Sora sees a vision of Vanitas standing next to Young Xehanort is due to Ventus' heart within Sora reacting to Young Xehanort's presence.

One of the sleeping worlds Sora visits is called Pranksters Paradise. Which is based off of an amusement park in Disney's adaptation of Pinocchio. In the film however, the amusement park is called Pleasure Island.

Many fans were upset that this games intro was not saved for Kingdom Hearts 3. The developers made this intro different because it was released in 2012. Which is the 10 year anniversary since the first game was released in 2002.

This would be the only Nintendo system Kingdom Hearts release that would be fully re-released as part of the HD Collections as Kingdom Hearts Re: Chain of Memories (2007) the PS2 updated version of the GBA game Kingdom Hearts: Chain of Memories (2004) was used instead, and both of the DS releases Kingdom Hearts: 358/2 Days (2009) and Kingdom Hearts Re: coded (2010) were re-released in cinematic format only.

County of the Musketeers is the first world in the Kingdom Hearts series that is based on a straight-to-DVD Disney feature, rather than a theatrically released film.

The Secret Ending where Yen Sid reveals that Kairi can wield a Keyblade and wants her to be trained for the upcoming Keyblade War is meant as a tie-in to Kingdom Hearts III (2019). The events of Kairi and Riku's visit at the Mysterious Tower would be further expanded in "Kingdom Hearts Birth by Sleep 0.2 - Fragmentary Passage-" which was released as part of Kingdom Hearts HD 2.8 Final Chapter Prologue (2017), which also contains this games' HD remake.