This will probably wreck you if you have certain kinds of trauma (especially if you have them without realising it), but in a good way. It's also occasionally very funny.
It's not well-possible (or advisable) to summarise what you're in for here, but I will say that you may want to set aside a few days for reading it, since it can pull you in pretty heavily and there are some parts where you likely will want some time to process after or not be interrupted.
The more adult prequel to Echo.
As the characters are older, they have different (1910s-coloured yet seemingly timeless) problems that result in more varied genres of horror along their respective routes. Overall, there's a good mix of unsettling moments, respite, and even healing ones.
You can read this VN without having read Echo, though there are some call-aheads to it. It also assumes less knowledge of US-culture due to the non-contemporary setting.
Updates are roughly monthly, with usually one further build available through Patreon.
This RPG is firmly in the "come for the porn, stay for the story (and also the porn)" category.
The game will likely keep you busy for upwards of 12 hours in its current form (without being grindy!), though it clearly has a habit of staying on players minds far longer than that. Don't attempt to play through it in one sitting.
Note that releases are slow-paced, as the two developers work on the game between other commitments. So far each update left off with the conclusion of a 'chapter' of sorts, which together with fan creations makes the wait easier.