>>717578905I like it.
I'd compare it to Silent Hill, which was an obvious influence. In 2 specifically The foggy town just provides the background to working into James' psyche, while the exact nature of the place and the reality of our experience has little relevance. It's all about James and what he did and him trying to come to terms with it. The town is the tool enabling that process and is left vague and unexplained.
Similarly Signalis' events and areas are a tool for Elster to try to pick herself up and remember what truly matters to her, as she's dying and fragmented into all the parts she's built out of. She keeps repeating this cycle of reliving all her pasts, until she's stabbed in the eye (like Odin) and gains the secret knowledge she needs to have to remember and move on. (The same thing happens to Adler).
Whether any of it is real or not, or a metaphysically real dream of a Lovecraftian entity, doesn't really matter. It's all about Elster trying to remember what she has to do, the same way James' story was all about what he did.