It was hard for me to follow the concept, I guess, it is because you should match images of heal potions, so, maybe, adding some names to it (and maybe to characters) would do the trick and simplify the memorization (that way you can write down connections).
It has a great potential, where you can add deep emotional stories to the character, argue about the reasoning of why they got sick or even add some characters that pretend to be sick and always brag about new potions!