Thank you for the compliment. It makes me so happy that people are still playing and enjoying this game.
As for the Finana MaxLove, I'll give you a hint and then a guide.
~FINANA ACHIEVEMENT HINT~
Some of the points come from thinking or saying positive things about her in scenes without her.
Achieving her MaxLove is independent from getting her route. You cannot get both her MaxLove and her ending. The general way to go about it is to treat her nicely and think about her from time to time.
And here is the walkthrouh guide for all characters, made by DerRaptor64. Much thanks to him, he did it perfectly. I put it in an image link jere, but you can also still find it in his Google Drive file.
https://imgur.com/a/ninisanni-scenario-walkthrough-guide-Q4RG55D
And if you haven't played it already, I recommend the sequel too, Ninisanni Scenario 2: The Harem End. There should be a link on the store page above these comments.