I actually quite enjoyed this. A lot of choice and variety in content; there's a lot of weird and niche stuff to indulge or ignore as you please, and your interactions with Theresa allow for a lot of customization. The developer updates quite frequently, which is nice to see. Lovecraftian themes are not new to eroge, but I feel the author does a good job setting up an interesting atmosphere and mystery. The most major weakness is the art, but personally I'd take good writing over good art any day.
EDIT: Gonna be real here, don't think this game really went anywhere. The relationship between Theresa and the MC is incredibly stilted and feels like it gets more awkward over time instead of less. Also, the hamfisted sex ed / gender studies parts really kill the flow of the game. "Before sex, let's first engage in a detailed study of human reproductive biology." "I'm glad you're my first sex partner, even though virginity is a social construct which has historically been used to control women." Like, who the fuck says something like that during sex? The mystery part of the story is also very slow to develop and has loads of 'monster of the week' style incidents that kinda just feel like filler. Liked the concept, but the dev clearly has a vision very different from what I'd prefer.