A solid concept, a solid visual style, and a clear implementation. What I like about this game is that it is understandable. I always know what the rules are: they are explained very well right at the beginning, and there are no bugs or similar issues getting in the way. The game may be simple, but it feels cohesive, which to me is one of the most important qualities for a game in general, and especially for a jam game.The only thing I was unsure about is this: am I right in understanding that there is no AI opponent, and the game can only be played with two human players? If so, that is definitely a drawback, unless I simply missed something.
In terms of further development, I would think about giving the player a clearer sense of the probability of drawing certain cards, possibly expanding how the cards work, adding special traits or battlefield variety, and introducing different card types. And of course, an AI opponent would be a very important addition. It feels like this could grow into a genuinely solid puzzle or competitive game.