Nintendo Universe writes:
Strikingly, Kingdom Hearts 3D [Dream Drop Distance] feels more like the next core instalment within the ever expanding franchise, rather than the inevitable spin-off identity that it’ll most certainly be attributed to.
Serving as a precursor to the oft-demanded Kingdom Hearts III, it traces that journey that Sora and Riku must undertake to become true keyblade masters. To do so, and a necessary preparation for the eventual return of Master Xehanort, the powerful sorcerer Yen Sid tasks the young heroes with completing the Mark of Mastery exam. 9/10