this game is fantastic. deck-building suika-like is such a cool concept. and then it takes it in so many interesting directions, in particular i love how there is this tension with the potion upgrades--you want to micromanage which potions you have left on your shelf at the end of the level so that you can choose what to upgrade.
i got to the cow witch before losing. i almost beat her, but i slightly misplayed and my potion overflowed. in particular, i thought i would be able to add the orange potion but it seems like the overflow started happening right as i was adding it. this did feel a little bit unfair to me, as well as a couple other moments--such as against the witch who shrinks your ingredients, when i finish my potion and she throws in a catalyst, it seems like my potion ingredients get worse as they are being activated which just feels mean.
still, those aren't really that significant of problems, and they were probably compounded by browser lag. but this game is so good that i got hooked almost immediately and just played through instead of switching browsers. so, maybe that says something lol.
my only other complaint is that rounds can really drag out. the round against the shrinks-your-ingredients witch might have lasted like half an hour by itself, as every time i made progress she'd counter it almost perfectly. the round against the bovine witch also took way too long to lose (i.e. she didn't finish me off quickly once i was doomed) which was kind of annoying.
still, all my complaints aside, this game is really solid. it looks good, throwing the potions in the big pot with all the clinks and clanks is great, and the way the mechanics interact just seems really fun to me.