GREAT artwork.
It took me way too long to realize I had to hit the damage card with the red cursor! I don't see that written anywhere, but maybe I missed it? I think it would be simpler if you just had one cursor that can trigger the cards.
I also think it's frustrating to have 8-9 cards left and get dodges all in a row...even when I got the hang of it, there was nothing I could do to beat the tutorial enemy.
I also made a rhythm game so I feel some of your pain and ran into some of the same design problems, hah. Rhythm games are hard to make! I sympathize.