Kingdom Hearts III would be an incredible game if:
-The gameplay didn't have such a silly "press X to win" mechanic that was introduced in KHII. It also would help if the series had some of the "free roaming" feel of KHI's gameplay, as well as keeping the speed of KHII.
-The characters weren't as terribly drab, impossible to relate to, hard to like (if you had intelligence), and really, aside from most of the Disney characters and a small amount of exceptions, the entirety of all the characters weren't that great.
-The story made cohesive sense, and it flowed from the previous games without confusing everyone who did or didn't play the previous games. I mean, KHIII doesn't need to have as good of a story as say 007: Skyfall, but my goodness the series so far has had terrible series, and quite frankly, it's pretty sad.
-CAN WE GET SOME FREAKING DRAGON QUEST CHARACTERS IN THE SERIES ALREADY!?!?!?
-Everything right in the series stayed, and hopefully was improved upon.