I didn't expect that any NDS game will still surprise me.
The main 'feature' of the game is the "time-line" - you can basically move back and forth in time changing your decisions and checking how story will unfold. There are two main story lines that you have to explore in parallel in order to proceed. It's a really interesting trick that makes you feel dizzy, but at least you can't complain about being bored.
There is an annoying part of going back in time - you have to revisit all history from a given node point (point in time). Sometime you have to skip a good deal of dialogues to get to the next crossroad which let you change your decision (which you previously made wrong). Most of the time it isn't that bad, but if you wish to complete all subquests (as I did), it might get a little painful.
Another great aspect of the game is the fighting system. It centers around a 3x3 grid on which your enemies are placed. In your disposal (or rather: of your characters) you have a wide range of various skills, and they are the heart of every battle. Apart from typical elemental attacks, magical buffs/debuffs/heals, you can use "move" skills. These skills are nothing more than attacks that aside from dealing damage will "move" your enemies. By well planning your actions, you are able to stack your enemies into groups, and attack all of them at once instead of dealing damage to a single mob.
Graphics are OK. Nothing really amazing - just really well done. On the other hand, music is great. Never distracting and well composed.
Bottom line is that while there are some aspects of the game that might irritate you, this is one of the best RPGs I've played on NDS for a long time. Just give it a try.