A fun game, not my personal favorite though
First thing first, the storyline to this game sucks!!! Its interesting, and might hook you, but this isnt a story game. You play as Marche, a kid who through the use of a book he bought, accidently transforms the whole world into the "Final Fantasy" world. Marche loves this world at first, but soon realizes he needs to head back home. Now his friends don't like his new ideas of destroying there perfect world, so you'll make friends and enemys.
The biggest change is probably how you learn abilitys. You learn abilitys by equipping weapons and armor. You get so many ability points after completing a battle. When the certain amount of ability points has been obtained, the abiliy is mastered and you no longer need to use that weapon or armor.
Another big change is the addition of judges and laws. Basically if you use an ability that that law phohibits, the judge will give you a penalty or take you to jail. Jail isnt that bad though, you can bail your team out.
Another big change is that your characters wont die permanetly. This makes the game excessively more easier, but this game is pretty challenging.
This game is really good, not storywise but gameplay wise. Some people will enjoy this game more than others. Have fun with it though.