Brilliant concept, I found myself spending quite a bit of time at the start of each floor just planning the best path in my head for the hero before I placed my cards. I encountered the card bug (which I see you already know about) but I just restarted and was more careful with my card placement because I wanted to see how far I could get and what else would be added at later floors. I managed to get to floor 12. I could see myself playing something like this outside of a jam, I would just maybe lean more into the players consideration of card placements, maybe with the enemies and benefit cards all being more powerful? or maybe slimes that grow and get stronger the longer they are left alive. Great game, I'll definitely come back to it if you're going to be making updates after the jam