It it very good.
Gameplay is typical of any RPG adventure, whilst the combat mode employs a kind of interactive turn-based fighting, a-la final fantasy. You select enemies and then an attack style, whilst pressing certain buttons will augment your attacks to cause extra damage. It works really well and ensures that combat isn't repetitive as you are continually learning to master moves and attacks.
Don't pick it up unless you have a lot of time to play games ! I found the campaign to be substantially long (30 hours or so), only occasionally feeling drawn out or competitive. Lots of side-quests to complete as well once you've finished the game.