The art, characters, and aesthetics are great and the gameplay is something different from your everyday card battler. But I found it quite an easy game to solve, if you create a +35 Purity card in your first 2 turns and then copy it in your next 2. If you want the game to be more of a challenge I suggest doing something like, only villagers you didn't treat offer their abilities. Or at least having the selection of abilities be more limited and random. Or changing the duplication ability (maybe it can only hit an unaltered card).
Also in the card designs, some are clearly better than others; -2 sick and -1 sick/+15 purity are both better than -1 sick which in turn is better than -1 sick only if 50+ health. Sticking to balancing more powerful effects with drawbacks is a good plan.
I didn't like the coin flip abilities, but I did like the play where you intentionally damage a character at 100 health so you can heal them up again and get the bonus card. True medieval leechcraft!