absolute banger. great presentation and a very smart core idea.
there aren't any complicated controls or mechanics to teach the player (which is very useful in this case), so all the fun comes from learning about different enemies, what they do, how hard they are to beat and even how you can use them to your advantage. considering this + there are cards that also remove some existing enemies you get a pretty decent possibility space and the game actually encourages thinking on your feet :)
something that came to mind as an idea to expand is that you may eventually start giving player upgrades, but they would just be randomly assigned to you and instead of being straightforward and making you stronger they would alter your playstyle in some way. that would make the player have to adapt their enemy-picking strategy and introduce even more variety/complexity. i don't expect you to work on this post-jam but just thought it'd be fun to share
thank you for the experience!!