I really like the graphics and the vibes you got going. I especially love the faces the cat makes. Give it more expressions! (maybe it could look more unhinged and dangerous the closer you get to filling up it's magic)
it took reading the instruction text twice to understand the tier systems, and the goals of combining.
I recommend an interactive tutorial (lots of work) or better yet, something that makes matching cards glow or shake or otherwise indicate that they would create something if you combined them.