Thanks for the amazing feedback.
About the difficulty I'm not exactly sure how to tweak it, because right now it's just multipliers depending on the wave and stage. This is I think fair after doing some testing and easy start is not an issue because next stages are harder.
About the deck, I know it's a big issue. I designed it in a few minutes from the cards I made before. I originally planned to give player a choice of 3 decks and maybe even ability to buy packs and edit the deck, but I didn't have enough time to make more cards.
Omce again, thanks for feedback, I will make sure to apply some of your ideas when I have the time to improve this game after the jam.