Less than 20%? If the release date at the home page is correct and the updates have always been this regular, then we're possibly looking at multiple years (plus an enormous VN) before we get to the end of the game. That's kinda rough. If that's the case, I'm at least hoping that maybe we'll be having the focus on each route seperately rather than all at the same time so we can at least get the story further forward faster. If the dev is simultaneously working on both routes and is planning on finishing them at around the same time, we'll be waiting for a looooong time.
There are no parallel routes in the game at this time, at least not in the context you're thinking. There are certain flags that are affecting dialogue, but they're all going to wind up at the same place as the game progresses, it's just different ways of getting to that point. "Good/bad homie" is already starting to become less important as Rin has started to forgive him for his action, and the "Good/bad uncle" flag will likely just determine when or how the game actually shifts into the next stage.
At the moment, we're in the "harem route" which would be more accurately called the "harem phase". Note, it's called the harem route, but the developer has been very clear that it isn't a true harem. Most of the girls won't be cool with it, and given what we've seen in-game so far, when certain girls find out what's going on heads will roll. Possibly literally.
The harem phase will transition into the "dark route." Again, it's more accurate to call it the dark phase. What he means by dark is a bit unclear, but based on Ami's rants, I'm suspecting it to be a bloodbath where death is only temporary due to resets.
The dark phase will transition into "purity routes." This is the only time there will be parallel routes, but they will be developed one at a time. This is where you choose one girl and play a single-girl route through to that character's ending, and then get sent back to the choice point to repeat the process with another girl. Once each girl's purity route has been completed, the true ending will be unlocked (and he's announced it will NOT be a harem ending).
We are looking at 5-6 more years of development until completion, most likely. The dev is very specifically setting out to make an absurdly long VN, and has been bragging about it for nearly two years.
