Major bug
I am level 9, so I have played a fair number of games by now. Never seen this bug before. Was dealt my hand. I swapped a card, worked fine. Tried to swap a second card and a space appeared with no card. Sure enough, my deck had a space in the middle. In fact, shortly after the game started, my opponent used one of those taunts to say something like "something amiss?" I assume my opponent was like "wtf?!" as well. The game played normally. When the second round began, there was a hole in my deck where a card should be. With a little luck, somehow I was actually able to win the match. However, at the very end, when my opponent was out of cards and all I had left was my blank, it did not automatically end my turn. Perhaps it would have... in some way... been possible to play that card if I clicked on the blank spot and happened to place it on the right spot. But it seemed unresponsive the entire time.