I like Kingdom Hearts. At least, most of the time. I'm not a raving fan like some people are, but I like it. For every new installment of the game, Square Enix adds something exciting, or at least something new, something that makes the game feel fresh. In Dream Drop Distance, they brought in some new mechanics, and even repaired old ones. While some of the earlier Kingdom Hearts games weren't as exciting, Dream Drop Distance feels like a new experience without dropping the Kingdom Hearts feel.
The newest mechanic is a mechanic that lets you capture enemies, and make them your allies, rather than have the same allies that you had in the old games. It's always sort of been a dream of mine to be able to recruit enemies to your party, and now it's possible. You get one of these allies by creating them like you used to be able to mix items in the first Kingdom Hearts, and afterwards, you can customize and bond to them much like you would a Nintendog. These allies can assist you by linking up with you in battle, and using special supermoves to aid you. They're useful, when you're in a pinch, but sometimes hard to use, as the character can move a bit too fast or slow when in link mode.
There is a system called Dream Drop, in which you play as either Riku or Sora. You have a meter at the bottom of the screen that times you to see how much time you have left playing the one of them you are playing now, before the game with them ends abruptly, whether you're in the middle of a fight or not, and shifts you to the next character. It can make the game and plot choppy, (which makes a hard to understand plot harder to understand) but it keeps you playing.
There are other new mechanics that the touchscreen uses. Usually games don't make useful mechanics with the touchscreen, but I've found that there are no flaws here. Basically, by sliding the stylus across the screen at certain points, you can jump around certain areas of a map at higher speeds. It makes travel, and sometimes fighting, easier.
Besides those there aren't any new features, but some of the features from the old games, things like the inventory, the graphics, and the new world flying, make the game feel fresh and new. It feels like I'm actually playing a sequel, rather than the same game over again. Perhaps because that's because they wait so long between games, rather than a few months like some companies. But that's my opinion, and you have yours.