Really love the idea. Sadly it feels extremely repetitive to me. I played the same 3 cards like 10 turns in a row to defeat the first enemy, only to get 1 new card and have to fight the same enemy again. I didn't feel like I was making interesting decisions each turn.
However, I really love the art and the sound effects in particular are superb. Overall nice work, would love to see more focus on making the gameplay engaging!