This game is designed to be heavily addictive, and it mostly succeeds at that - between daily and weekly tasks and the endless mission of earning more coins to get more packs to get more cards to build more decks, you've got a lot of stuff to do in this game.
The problem is that progression is pretty slow, and you start out with a pretty lousy selection of cards. The result is that, instead of being able to build a variety of decks, you can build basically one of two kinds of deck to start out with - either some sort of aggro deck, or a midrange deck. Neither are great options given your card selection, but you can at least function.
The issue is that, because of the slow progression, you're not going to get enough cards to build an adequate deck of any other kind for a long, long time, resulting in you playing a very similar deck for a very long time. After dropping 30 hours into the game, I had maybe 20% of a small expansion complete, and was still playing more or less the same deck I had started out playing.
The story matches are decent enough - you get to play a greater variety of more interesting decks there - but if you actually want to play a decent deck in the deckbuilding mode, you're going to have to either sink an inordinate amount of time into the game, or sink an inordinate amount of money into it in order to buy tons and tons of packs to complete sets, as you cannot trade for or otherwise acquire the exact cards you need.
My recommendation is to steer clear unless you want to try out the story campaigns. The reality is that a lot of the fun of Magic comes from building the deck you want to build and playing that, and this game just doesn't allow you to do that easily.
2.5