This is what I think should've been added:
*New harder difficulty mode called Kingdom mode. This can only be unlocked by completing proud mode and all of Jiminy's journal.
*Freeroam mode. A mode that is unlocked after you beat the game on any difficulty( inluding the unlockable difficulty above) and it is activated by soft reset. In this mode, you can basically do whatever you want. Here's some of the features:
-Destiny Islands is unlocked and can now be explored.
-New jobs are available on a few of the worlds including Destiny Islands. Some jobs give Sora money for his labor. Some of them are just for fun. A few of these new jobs are Materia hunting( work with Yuffie. Can only be found on Radiant Gardens)and Heartless hunter( Sora by himself. This job makes you go all over the place and some of the enemies you go out to fight are new bosses like Malificent, Pete, Kurt Zisa, Kadaj, and much more. The heartless hunter missions can be accessed any time you want and it never ends, which means several of the bosses or enemies you faced on previous hunting missions will appear again and again but in different locations. And there would be a large variety of bosses and enemies).
-Castle Oblivian is unlocked and can also be explored.
-New mini games are unlocked including a blizt ball sporting league on DI.
-New gummi ship missions are also unlocked
-Drive is no longer accessible but duel wielding can now be used freely.
-Reminiscing mode. This can be accessed in Radiant Garden, Atlantica, Twilight Town, and Destiny Island. This feature allows you to relive some of the classic boss fights from the story mode.
-All the costumes that Sora wore in the game are accessible and can be put on any time when Sora is inside his house. Several new costumes like the Org. coat are also unlocked and can be purchased at certain stores across the worlds.