The Length of the Game
Maybe it's just me, but I felt like KHIII was the shortest game of the series. Well, at least the ones I've played. The first game, Re-Chain of Memories, the second game, Birth By Sleep, 358/2 Days, and the third game.
I know what happens in Dream Drop Distance, but Re-Coded and all the X ones...I'm completely in the dark...
I kind of tried to breeze through the game to get to the final battle, so that my fears from seeing the final trailer could be cured. I also wanted to see if what I've been waiting for since the first game to happen, actually happened! (Brownie Points for anyone who can guess what I was waiting for. I'll be saving that complaint for last)
Maybe some think it was longer because they went out to find all of the Lucky Emblems. I found more than a few, but not all of them.
Also, there were no Tournaments at Hercules's World! I loved those things, from the first AND second games!
Plus, no optional superbosses like Sephiroth or Terra's Lingering Will! Now, I'm not saying they should have brought back the One-Winged Angel, and Terra's Lingering Will wouldn't have worked; but give us something at least! Maybe something new and original...
Any of those last two things could've made the game longer.