Really nice job! Rare to see such a creative set of mechanics, really required some thinking to create a strategy.
For me, it was somewhat easy (won on first try), but I did lose a few villagers. It *felt* hard, but actually losing was difficult.
It might be worth laying out how the sickness mechanic works. The text was really hard to read (on my browser, the mouse obscures the explanation text no matter how you move, Safari OSX), but also I don't think anywhere explains how the sickness is distributed. Same for disbelief. Even if it's random, it would be nice to know what kind of random. Randomly in the night? Randomly upon losing faith?
Also, the nights were confusing. Why did some villagers not come to see me during the day? I often had someone die because they did not come to see me (maybe for multiple days in a row? Unclear).