9 chapters specifically. The dev is particular with numerology. A lot of 3s and 9s around the game. They're resolving many of the mysteries in this chapter anyway so I reckon we're now in the last act.It's a good game that releases a new chapter every few months. We suspect it has 10 total chapters (judging from what the developer said about 6 chapters being past the halfway point) and we're currently on chapter 7, which was just released yesterday.
I find the game great, although it's not just a simple visual novel. There's quite a bit of depth and building to it. Even if you're not interested in all that, the game, hands down, has some of the best and most polished CG's of any visual novel I've seen. If you want some awesome CG's without the hassle of the story, just use unrenpy/unrenforall and unpack the RPA files to look at them.
So after this, there's only 2 chapters left, with each chapter cooking for 5 months. The game will be finalized and fully packaged after a 1 or 1.5 years.