This is a really cool concept, and executed with a lot of mechanical depth and delightful animations.
My one suggestion would be to further integrate the tutorial into the game, rather than having everything explained all at once. It's definitely not game breaking the way it is now, but it delays the much more compelling hook when you actually get to make real choices about the cards.
Awesome! Yeah I think limiting the player's options and making the first enemies pretty straightforward is enough to show the player the basic mechanics. The cat's explanations are good, but I do wonder if they can be pared down.
Really solid mechanics though, I can tell there's a lot of depth to them. And they are complex so it makes sense that the tutorial would be a tricky thing to perfect.