itch.io

It's already out in his patreon, I think Luriel just forgot he had not posted it here in itch yet.

First, you need to study at home for the cure, and you will learn the recipe for spectral syrup (the cure). But the recipe needs a mystery ingredient, Heat Occisia. You can ask the priestess at the temple about it, and she will teach you how to make it.

I am assuming you have already studied your book for all the standard recipes, because you also need red and blue pulps as ingredients

It's not a beta, 0.22 is the patreon version. Itch offers one earlier version for free (0.21, the one you can download now). When Hyao finishes 0.23 they will post in their patreon, and update the itch one to 0.22 (usually once per month unless there are unexpected delays, so 0.22 will update any day now)

But before you do that you need to accept the quest from Bernard to make the potions.

Once you get the "find the acolytes" quest, which open new areas of the swamp, you will eventually find the witch hut exploring there. 

There are two witches, though, one by day and another by night, and they give different quests and sell different items (you can visit both)

To talk with the merchant you need to finish the bandit camp questline; a new area to the north will open after that. The merchant caravan is one of the encounters when you explore that area

It's probably because your development log. The last update you announced was in February 2018. The same happened to me than the OP: I thought this game was abandoned for months, until one day I ended up in the game page browsing new games and I noticed the version to download was already in the 7.x while my game was still 6.x (I don't remember the exact numbers)

The heat occisa is not the cure, it's just one ingredient of the cure. You should have something called "spectral sirup" in your potions list.

Once you realize that your character is an alchemist (duh!) the game becomes much easier. Use potions. Lots of them. You can win without them, but I am fairly sure that the game is meant to be played with potions.

Once you complete the bandit camp questline, a new area of the map will open north of it. Hidden in a cave you will find glowing plants, and you can get someone you already met (I won't spoil the details) to turn those into a light.

I am loving this game, even though it is still on the starting stages it is already one of the best on itch, good work.

Though I have been wondering from the start... is there some additional purpose for the gay/straight/dominant/submissive potions? Because I have played the game several times and I don't see how you will not have your sexuality preferences already set up the way you prefer (via normal gameplay) by the time you are able to craft things like aphrodisiac or black pulp.