This is my new favourite game !
My boyfriend showed this game to me yesterday, it's called Duelyst and it's so cool I can't stop playing it. It basically works more or less like Hearthstone, except your cards are summoned on a rift and you have to move your creatures to attack your opponent.
It's kind on a mix between Hearthstone, chess, and with Final Fantasy graphics/fights :
Anyway, just go and check it out : Duelyst
Here's the presentation trailer :