If you are new to magic this game will give you a good introduction, for experienced players not much flexibility.
So far i have only tried the AI campaign and for the most part, the computer plays pretty well and can offer a good challenge on the hardest level on occasion.
The biggest issue is the fact that there is no flexibility in your decks. you must play with the pre-made deck. You do get some added cards as you win duels, but the base deck does not change. Part of the intrigue of playing magic is being able to make a deck and experiment with various combination's of cards.
I think this game does offer up some fun for people who may want to try the game without the major investment needed to play the Online version of the cards themselves. But ultimately you are limited and may get bored. At best this is a welcome change from the normal games I like to play. But it will not replace them.