LK is very short (I clocked 8 hours until first finish). The game has a good gameplay, though. It was probably concepted for being played against a friend, the story seems more like an excuse for singleplayer, which is simply the mode where you collect the cards for multiplayer. I have never played it against a friend, though...
If you're looking for a good RPG, get Skies. If you haven't already, that is. And PSO is good for hack'n'slay fans and has a loooong play time. BTW, does anyone know whether Mystic Heroes is a good game for H'n'S?
And don't get fooled by LK claiming to be an RPG. It is action-strategy. You don't really level up, EXP is more like a currency used to get better cards.