So I've got two points here.
First of all, I'd like to congratulate the people at Bethesda and DWD for the surprisingly furnished card game they just released in open beta. As a casual player of Magic (and sometimes Hearthstone), it's nice to see a CCG that's very solid right when it hits the streets. But I'd also like to voice my displeasure in regard of how the game creation/editing process lacks transparency. Unless I haven't checked at the right places, there is no way to have an idea about the frequency of arrival for new content, or what the devs are aiming for in the game, what they are trying to accomplish right now, what we can expect; basically, it all lacks transparency. I'm thinking about Epic's Paragon when I say that, which is a very good example of a game that invites its community to apprehend and understand the thought process and progression of the game. It might seem simpler to keep that all behind close doors, not to worry the community with it , but it really creates an unwanted distance between the two in a game so early in its development - which is something you do not want. I'm assuming that you have the means for that kind of community management - if you don't, or if you were planning on being very transparent in the near future, or even if I'm wrong and you're already doing all of that, then my apologies and forget I ever spoke about that.
Second is what happens when you have cards on the field that are in a position to attack. It's very frequent that one doesn't orders them to attack, for various reasons, but it also happens very often (for me, at least) that I click the end of turn button without realizing that I have cards that I could use to attack. Of course, you could tell me to pay more attention -which I am trying to do- and you could also suggest to the developers that cards in such a position are made more obvious than just hovering above the board (like, say, make them glow brighter, or whatever). But I would advocate more for a togglable option in the menu (the game is in dire need of more game options by the way) which would make the game warn us when we have these unplayed cards on the field. Just a "You have unplayed cards, would you really like to end your turn?" would be alright.