I have no idea how it managed to be as horrifying as it was. The atmosphere was very tense, and the 'monster' encounters were legitimately terrifying despite being so seemingly abstract. Every time I had one, I found my legs goosebumping up, thanks in large part to the sound direction. It really sold the whole game, and so I get why you wanted the headphones on (someone tapped me on the shoulder while I was playing and I screamed.)
So, my amateur attempt to interpret it is that it's about someone who won't let go of their friend. That is to say, the 'monster' you encounter stops chasing you as the woman starts to understand she has to let go. Meanwhile the 'lights' were in some way significant because once she accepts letting go, they no longer light up. Similarly, I think the 'sparkles' have to be, like, a miscellanea of remembered objects that have significance only for their connection to the girl she fell in love with.
But what I don't understand, of course, is what happened. "Brain damage" is a strange tag. The first impression is that they just moved away, but with the impossibility of finding the house, the strange stories, the odd trees, it has this feeling as if it's straddling the everyday and something almost supernatural.
At the same time, that feels like it might just be the magic of childhood, and of romance, twisted and turned into some dark forest of mental regret. (And again the 'Fantasy' tag makes me question things.)
So yeah, I really enjoyed it, it was freaky and strange and very, very unnerving, and thank you for making it.