As Sora's new Drive Form, the Limit Form was not in Kingdom Hearts II (2005), it is the only Drive Form that Genie cannot imitate when he is used as a Summon.
Sora's new Drive Form, the Limit Form, which was not in Kingdom Hearts II (2005), in terms of appearance, as well as gameplay is a reference to Kingdom Hearts (2002) and Kingdom Hearts Final Mix. It is also the only Drive Form that does not require Sora to fuse with Party Members, allowing him to activate it when he is alone.
This is the only Final Mix adaption to have new cutscenes with audio for the main game. The Final Mix version for Kingdom Hearts (2002) only left these cutscenes silent, while the Final Mix version for Kingdom Hearts: Birth by Sleep (2010) only had new cutscenes for the unlockable Secret Episode mode (which the Re:Mind DLC from Kingdom Hearts III which is similar to the Final Mix upgrades would also take a similar approach to Birth by Sleep). The English version for the Kingdom Hearts II Final Mix cutscenes did not exist until the later release of Kingdom Hearts HD 2.5 Remix (2014) as this version was originally a Japanese-only release, with the only minor exception of the cutscenes that were adapted for Kingdom Hearts: 358/2 Days (2009). Additionally this is also the only Final Mix version to include actors through sound recordings or new cutscenes that were not part of the cast for Kingdom Hearts II (2005).
The new hidden boss Lingering Will in his appearance and dialogue is meant as a tie-in to Kingdom Hearts: Birth by Sleep (2010), as it was revealed in that game that his true identity is the playable character Terra, whose soul was trapped in his Keyblade Armor after Xehanort had stolen his body during the finale of that game and his dialogue in this game also references the other two playable characters from Birth by Sleep, Ventus (nicknamed Ven) and Aqua.
Like Kingdom Hearts Final Mix, this game also uses English Audio with Japanese subtitles. One difference, however, is that the Final Mix exclusive scenes for this game however are dubbed in Japanese instead of left silent like how it was with the first Final Mix game. This also includes seiyuu (voice actors) for the Organization members that were killed off in Kingdom Hearts: Chain of Memories (2004), who, at the time, did not have English voice actors for some of these scenes and the optional boss battles. However, the Japanese audio for the original cutscenes can still be accessed through Theater Mode.