Well, I just finished the demo. And I must say I am impressed. you really hit the spot of my taste. I think the writing is very good, the story is interesting, the caracters charismatic, the voices aren't bad (just the girls have watched too many animes instead of american shows and are disguising the voice a little too much, but it is good), and the drawings are very good.
As for suggestions, I have one, some people will disagree with it, but here it goes: To better the presentation of the game you should think about including some CGs of the action moments, for example: a CG of Jilly trapping Matt in her slime, or one with her throwing his sword away, or one of Tari dragging him to the coffin, etc..
I know many people will say: "If you have money for an extra CG, make a sex one" and I understand them, but I really think most of Visual Novels just worry about the sex and the writing and forget its presentation. I really would preffer less sex scenes but with the rest better presented (with action CGs to illustrate) and with that better understood than more sex scenes.
And for the last, I may not be able to contribute right now (unfortunately Brazil is in a crisis, and I am jobless), but I have full intention to donate once things gets better, You really impressed me with the demo and I hope you guys can achieve the success you deserve.
Just one last question, it wasn't very clear on the patreon, but will this game be freeware once finished, or you are using patreon as a way to sell it? Since some others indie developers are doing this kind of stuff I thought I should ask.