I like the concept of this game, but it just feels horribly unbalanced and almost entirely luck based.
I never feel like my choices ultimately matter all that much, because I don't get to decide what is played. I could have a deck with great synergy, but if that Ant that gets played is the card that tips the damage over the threshold, I'm then screwed, because I'm left defending the crown with a card with 1 health on top of a huge stack of cards that are obviously going to overfill my den.
I feel like having a hand that you draw into would be better, and perhaps letting us choose which animal in the den is hunted? That way I can hunt my Ants or Bees and leave the Bee Hive alone, because losing an animal that's central to a build is not in my control and run-ending.
There are also some cards, regardless of quality level, that are objectively better or worse than others.
Like I said, I like the concept of the den and draw deck being the "health" of the player essentially, it's innovative. There's a reason that most other games have very limited permanent changes to your deck, though. It's incredibly tricky to get that to be balanced. If you can get that to work, that would also be a really cool feature of this game, but as it stands, literally everything being permanent makes it too hard to balance a build, and makes it largely luck based.