I think that this is a good start for a game, and really shows a lot of passion for what you do, which I whole-heartedly support, but I think that the story is a little... shallow? I mean, the message is loud and clear, but it feels more like a scary PSA than a real art piece, and while that kind of clarity is important to ensure your audience understands the message, there are a lot of better ways to express that than just saying it outright. Horror is a very nuance-based genre, and some of the best horror films (really, films in general) leave you thinking about what the symbols (both literal and literary) contribute to the overarching narratives at hand. Over-explaining certain details and being upfront about things may be nice for the shock factor, but it rips the nature of discovery from the viewer.
The ideas you had are really good, and I'm a fan of the puzzle systems, just maybe try to dig deeper into what is really horrifying about your story.
Keep up the good work!