not for the demo, but for the full game? Yes. Because it’ll (probably) be like a 4-5 hours gameplay with multiple endings.
Hi moona! I'm really flattered that you're interested in making a fangame of my work, really. I truly do appreciate that. However, I'd like to clarify that I don't give permission for fangames to be monetized, especially if they use my characters. It honestly makes me extremely uncomfortable. Thank you for understanding. 🙇