Upon playing some more, I notice a couple more things. Notably, yeah, the Spirals and Eggplants probably need some tuning-down. More specifically, when they show up in as high of concentrations as the enemies have them in, they're very quickly overwhelming, to the point of being unfair. The same excessive amounts also applies to the Cowbells, although that's to somewhat of a lesser extent, since they are single-use. At that point, your only hope is to get them to overflow, and do all that to themselves instead.
I find that the Bulging potions are relatively fair on the player's side, since you don't get them in as high concentrations. I imagine the same goes for the Hypnosis Potions, but I never got any to show up, so I don't know. Although, they are generally just better than the eggplants, since they give a passive Allure bonus alongside taking up space. I feel like making the Spirals not be persistent, like a variant of the Slimy Potion with some bonus Allure tacked on, would be good.
Also, speaking of Slime, I feel like it might be good to make them not "pop" upon hitting max level or something like that, since their entire purpose is to be space-blockers, and it kinda defeats the usefulness of using a bunch of Slimy Potions if all the slime they drop gets merged and liquefied.
And a minor thing: It would be nice to see the other witch stay on screen a bit after winning the level, so we can see how our last brew transformed her.
Anyway, sorry if it feels like I'm being overly-critical, or backseat-devving (if that's a thing), I just really like the game, and would love to see it improve.