The sound is great, and I love the design of the different potions. Especially the little paw prints in the animal speak potion.
I liked the surprise of seeing what my ingredients would create, and as others have mentioned, the color changing is a great detail that made the world feel responsive to my actions. At first I thought maybe it was possible to add multiple of the same ingredient and get a potion, but if there's a recipe like that I didn't find it. With four ingredients I quickly figured out there were four possibilities and completed them all.