Well, got it, played it.
I didn't expect too much for $10, however it is disappointing.
Deck building: Ok, I wouldn't expect the full deal in a game like this, but the way you add extra cards and it auto adds lands is terrible, gives rubbish results.
Challenges: These are good, but relatively simple if you've ever played magic beyond a real basic level. If you haven't got much experience or are completely new, they possibly could seem difficult and don't help you to learn the subtleties some of them may require.
Single Player Gameplay: I find some of the timers are very short, it can be difficult to time certain plays correctly. Lands are auto tapped, not necessarily the ones you wanted to tap in multi colour situations.
Multi Player: Buggy, matchmaking system, had a hard time getting a game.
Co-op: Apparently it's hot seat only or some such deal by the whining on the forums, can't say I've looked at it.
Not a good product in my opinion, even the old dos based game still plays better than this
Wouldn't recomend it even as a basic introduction to magic.