Amazing concept that was really well executed! It honestly felt like i was playing the demo for a fully finished product. I got stuck on the third fight but I can tell this has a lot of potential to be turned into a full game (if that's what you want of course)
Some minor suggestions I have would be to maybe add single use abilities such as forcing a chosen card to be played? I don't know if that would work at all but it seems like it would make the gameplay a bit more interesting. Maybe also a choice of which card to take from your enemy, just to add a little bit to player agency. Regardless of whether either of these ideas would work well, this game is very well done. Easily one of my favourites so far. Great job!