There is an extremely good storyline to the game. You are a boy whos dad died as a guardian and now your invited to join the guardians aswell. The offline play is really good, you dont have to always do story missions instead doing other alternate missions to get your lvls up is a good suggestion. Instead i just did the storyline.
Completing the whole game gets you an easy 1000g. They all involve killing different bosses. This lasted me at least 20 hours of gameplay and the fun didnt stop. Online is where its all happening, you join other peoples parties and do missions.
How ever online there is a catch which involves a small price to pay. Its an extra payment like xbox gold but a couple of £ more. It was definately worth the money tho as you can play it for hours on end. The creators even put it in special events at halloween and christmas.
If it wasnt for the additional payment i would have given it 5/5. Other than that this is worth getting. Its different to any rpg game i have ever played and fighting creatures never gets boring.
I would suggest getting this game and giving it a go.