I'm not usually a fan of visual novels, but this definitely has my attention because there's more to it than just "Make dialogue choices and hope for a good ending!" I don't care how great the story is, those are just a waste of time because they aren't engaging at all. This one is because of the puzzles.
That said, the puzzles being tough is only BARELY enough to make up for there being only one per chapter. What's more, there are two problems I have with this. First, the fact that it takes the player back to the menu instead of proceeding to the next chapter- or better yet, asking the player if they wish to continue to the next chapter. It would save people a lot of time.
The second problem is that there's no option to erase your save. Yes, you can replay chapters, but unless you tell us otherwise here, I'm not sure that our paths in the chapters can be changed by playing previous chapters more than once. For instance, I'd like to pick the Red Door in Chapter 8, but I already chose the Green Door. Now it says "Ink refuses to listen." There are three possibilities: Either the Red Door is in chapter 10 and choosing that takes us directly to it; this is the one "choice" that is truly an illusion in the story; or my first playthrough cemented the choice right then and there.
Actually, I'll figure that out on my own by playing on the other site. I'm sorry I won't be able to tell everyone here directly what the result is. Maybe someone who reads this and hasn't written a review yet can message me and I'll give them the info.