I started playing this game a few days ago. I can't talk much about how fast/slow the development is, but the current state is great.
Worldbuilding is actually interesting enough to keep me engaged outside sexual content. And while the idea of new areas opening as you play the game is not new, it was well executed, it doesn't feel forced.
I don't typically like 3D because it falls within the uncanny valley for me, but here it looks great, and the characters look pretty. (I've played worse. Sisterly Lust for example.)
There's no Mary Sue but a bunch of flawed but still likeable people. With surprising emotional depth and surprises - for example, Naomi can be rather fragile and Yona insightful, you don't really expect that from them, nor Lyriel being sweet. But by far Rae is the best for me, the sort of character that makes me wish for a happy ending.
I wish some warning icon popped up when you can progress through the story doing something in a certain room; I think Bubbles and Sisters has it? Checking through the questbook all the time is a bit of a chore. I also wish that the map was an actual map, instead of just a list of rooms.
