Well made, bug free at least, from what I saw. The screen is extremely crowded and confusing; it looks like cardboard cutouts. Between levels is cluttered and poorly designed.
I understand that it's a card game, and that luck of the draw plays a major factor, but a lot of the "challenges" are easy to lose on the first turn. When there's nothing a skilled player can do to prevent instantaneous death, it ceases to be a challenge of skill, and becomes a frustrating challenge of persistence.
I beat one of the challenges because the computer didn't attack me for almot 20 straight turns and megalomania stacked up to almost 40 arcane, letting me blast him for 50 damage when an attack card finally came up.
I think a deck builder of some sort would make the challenges a little more skill based, and a lot less random.