I see.
I won't say it is hard, but it is not easy either. Quite a number of bosses and enemies are pain in the ass. Perhaps this gameplay trailer will help you decide:
http://www.youtube.com/watch?v=Z88g8sCQJ9A
If your party's leader is KO'ed, then Game Over, unlike any other FF games. However, you have the option to Retry as many times as you want. Also, this game does not use Level Up system. However, it uses Crystarium System to increase your stats and learn new abilities. This system is similar to FFX's Sphere Grid System, except it is much more simpler. You need CP to activate a crystal node (HP, Strength, Magic, Abilities, Role Level), which can be gained by winning battles.