The premise was interesting, the pace was fast and I found it an addictive read but I guess that wasn't enough. When A falls in love with Rhiannon the story ends. It is just the two of them being all stalkery and cheesy and not romantic at all. I don't like romances in books because I think they are difficult to portray, your job is not to show me the love but to make me feel it and care for it. Here I didn't feel anything, A kinda forces his/her/insert here preferred pronoun presence upon Rhiannon and she is just passive to it.
I surely liked how the author wrote about sexuality and genders. The fact that A is genderless kinda tripped me for a while. I liked that we got to see many characters with different lives but I think that the obsessive thoughts about Rhiannon and love shaded their stories and I think they deserved to be told in more depth. It was a good chance to write about interesting issues and I think the author just wasted it.
Tiny little spoiler allert.
I hated the ending. I understand the author wanted to be poetic and wanted the two of them to fall asleep together and live like a normal couple for at least a day but Rhiannon had told A she needed some time on her own to overcome the feelings she still had for her ex. A, instead, thinks it is better if s/he finds Rhiannon a more suitable companion so she won't be alone when A will be gone. Because what says love more than a replacement of what you've once loved? Plus Rhainnon is going to wake up in the bed of a stranger, this stranger will only have fake memories of her. Isn't that creepy? Creepy and patronizing?