If you like turn based tactics games this is the one for you! Immersive gameplay, lots of jobs (classes) and sheer endless tactical possibilities and depth. Don't expect a deep story, expect very varied fights, some (especially in the first part of the game) rather easy, but some quite difficult. As you can change between jobs and have two different sets of skills there are numerous ways you can approach each tactical situation. Smart combination of your skills will be rewarded and the "Law" system* adds to the alure, as it keeps you from constantly using the same tactics and characters. Two difficulty settings add to the already good value for your money.
In short, there is no better turn based tactics game for the DS. Period.
*for each battle there is a certain restriction (like: no using fire, or no blunt weapons). You can still win the battle, even if you break the law, but you will miss out on some bonus loot.