Learning the unique mechanic was super fun, especially how easy it was to quickly get grounded in the mechanic. Got quickly repetitive once you handled the basics, however, regardless of understanding the more addvanced ramifications of the mechanics. So maybe just shortening the amount of enemies to beat at the beginning before progressing. That "I'm ready for the next thing" feeling came much sooner than the "here's the next thing", if that makes sense.
I needed a little more reminder of what the cards did and/or some sort of number display to help me understand the mechanics of what was going on at the end of the turn. Maybe the number of heal or damage appears on the card and changes whenever you place more pink cards around the blue card.
I'm not sure if playing the pixie cards was a strategy I was supposed to be able to do?
At some point an extra card slid down from the top of the screen that I could put anywhere and couldn't play and it just stayed there.
Overall I got really excited about the mechanic and I'd be interested to see what other layers could go on top of this. Layers layers layers! And great job scoping this properly for a game jam!
Voice acting was a fantastic touch.