What is the main goal of a digital version of a card game? The goal of adding metagaming around the core experience, being either with a story, with cards to collect, achievements to get or quests to complete, is of course the main draw to these remakes of games such as MtG. That being said, the main goal of a digital TCG is to portray as closely as possible the original game and to follow its rules the best it can. MtG2015 is terrible in many ways at doing so, especially since I've been playing MtG for the past 15 years and I was at least expecting basic moves to work.
After a small tutorial explaining the mechanics of the game and giving you the choice of a deck you are thrown into card battles against the AI or in multiplayer. The interface works although it's a bit slow and not very precise at times, but you could theoritically play MtG with such systems.
But it's apparently still too complex to make a digital version of a card game that won't drive you insane for a billion tiny reasons. This 2/2 vampire card that has 'Pay 2 life, vampire gains flying until the end of your turn' must really be important because the game forces me to 'end phase' at each phase of my turns in case I wanted to activate that ability, even the end phase after attacking when it would be completely useless to do so. That ticked me off, make the cards more intelligent about when they force you to confirm inaction, add a toggle or something.
And then I'm fighting against this guy throwing big creatures at me and I decide to block his 4/4 with a useless 1/1 and use the ability of another card to sacrifice the 1/1 and give +1/+1 to another creature. It's a fairly simple move, the 4/4 is blocked but takes no damage because the 1/1 is sacrificed. Not in MtG2015 you can't! There isn't a sliver of time between declaring blockers and activating effects. So my 1/1 blocked the 4/4 and simply died, and I uninstalled the game.
Because if I can't play MtG on this MtG game, why would I bother?