Surprisingly deep. Really enjoyed stacking the effects on top of each other, very roguelite-y.
I think the length of the game is perfect for the content, the grid could have been 5x5 to encourage more shuffling and have less dead space at the end. Although there's a lot of card potential with diagonals and elements to explore! I also only realized you could move cats on second playthrough xD
Super fun and short submission :p