Wow, this is pretty incredible! I made it to level 4 and can see myself putting an hour or two into a full playthrough. The gameplay seems like it could get really deep with all the new cards I saw. And the visual design and auditory feedback makes it feel really good to play. Just for a couple of suggestions, I would love to see some cards that can give you more energy, or the ability to remove cards from the deck. But overall, fantastic work!