This is excellent, well done! My only criticism is that since you need at least 8 villagers alive to beat the 720 purity requirement at end, the game should either end after 2 people die or the purity rating should be lowered.

Overall though, the art, sound design, immersion and game balance are very well done. It kept me playing for hours because it has such a good gameloop. You should be proud of what you have made here!