I wanted to beat the game with each character before I made a post, I've only lost with Reese so far in order to test the mechanic of breaking the game which while I enjoyed the scene I didn't like that the game punishes you for using the mage's mechanic.
All the decks seem pretty balanced (besides Reese), I think most of the negative feedback comes from people who haven't played a Dominion Style game before.
I think you should remove the mechanic that punishes you for using the mage mechanic to get infinite draws. I also think a clearer UI for what Slimantha is using would be nice as it all resolves immediately and it's sometimes hard to tell what happened.
Definitely love the game so far! Looking forward to some more scenes and possibly some animation loops?