good job on making your first vn! \o/
you've set up a strong dynamic between lizzie and arlinn, where they both need to rely on each other to have their desires met (arlinn and her masochism, lizzie and her desire for a personal toy.) the end has me curious about how their relationship will evolve over time — when they're more familiar with each other as people.
i like the emphasis on prose/nvl style writing over adv too, it really helps me get into arlinn's head with her (justified) fear of animals and going outside, and how that affects her mentally.