Oh, definitely agreed and I didn't even finish it or a route yet. It's that good <3 While I myself can't and won't donate, sadly, I'm baffled at this being for free as well.
I wish the devs would release it on Steam, maybe with some Artwork or Artbook or Walkthrough to buy (and the OST as well, if they are allowed to) and maybe could get some money that way to develop something as great as this or better.
One of the lore-heaviest and most unpredictable VN's with shades of gray instead of clear black and white, mysterious, greatly written characters and the perfect atmosphere, in my opinion.