A very striking visual style with the limited range of colours used - I really liked that there was an in-universe reason for the palette, very clever. The character art was charming and expressive, and worked well for the yandere-ish plot of the game. The little touches in the UI borders were impressive too.
Your notes mention being worried about the writing but I think you've done a great job with it! I liked the glimpse into a wider universe with the casual mention of ritual magic and the bonus snippet of lore in the About menu about the disease.
Great work!