Alright, I took a lot of notes during this one, so I'm going to do my best to condense my jumbled thoughts here. Ultimately, I think this had many bright spots where the strengths of the writing and its ability to highlight raw emotion shined, but it didn't really work for me as an overall arc. Looking through the comments, I see that they're almost overwhelmingly positive, so before I'm summarily burned at the stake for my heresy, let me try to break it down.
I'm mostly just gonna let this one rip in a stream of consciousness, so general spoiler warning from here on out.
Handling presentation first, I think this was generally polished and well-done. I have a gripe or two for each that I'll get to, but I thought the sprites were well-drawn and expressive, the CGs were gorgeous (even if the Kosta x Cygnus sex scene CG was maybe a bit gratuitous), and the music generally worked well and complemented the scenes.
Rapid fire notes on the above to get them out of the way:
- I don't really mind the "blank" sprites to depict total NPCs who appear for a scene or two and don't affect the greater plot, but it does feel off when the sprite clearly doesn't match how the character is described. For comparison, the security guard's species isn't defined, so the blank sprite works well enough, but the boss is explicitly described as an owl and the sprite used looks vaguely canine. Could just be a personal thing, but I'd rather not have a sprite at all than one that doesn't match the character (and this feels conventionally acceptable for a character with one scene, even outside of jam limitations).
- Music felt inconsistently used in scenes where there's diegetic music present. Just like any other soundtrack, music in VNs can be used for generally setting emotional tone (you have a handle on that), but it can also represent the music actually playing (or not) in the scene and use that to set the atmosphere. If Cygnus turns off the music in the car, turn off the BGM. If the crew is at a karaoke bar, don't turn off the music. That kinda thing.
- The phone screen text was a good effect, but there were times when the bottom of the phone screen was obstructed by the VN's dialogue box, and pressing "H" to hide the dialogue text also hid the phone screen text. I was still able to read everything okay, but that's a QoL thing that I'd suggest fixing if there was time.
That... wasn't exactly rapid fire, I suppose, but whatever. Writing!
The writing is good, and I want to make this clear right off the jump in this section. "Stepping past old ballet programs, folded laundry still in a basket, and the occasional knitted stuffed animal, you sit on the edge of their bed." is an excellent line that conveys so much detail about Cygnus without firing a minigun of metaphors at the reader. I did notice that the writing felt more comfortable once the relationship started to sour than it did in the more romantic first flashback. There's a lot of awkward phrasing in that scene that doesn't feel natural.
For example, "You've been really getting into my feelings lately" - I don't quite know what that's supposed to mean. Is that supposed to be "You've been really interested in my love life recently" or "I've been thinking about you a lot recently"? As another example, "I want your name in my mouth, and I want to struggle to say it between my breaths." I kinda feel like this was supposed to be an internal thought rather than actually spoken, but I just... cannot imagine someone actually saying this during sex. I don't really have a problem with the language used when Erin and Cygnus talk about their relationship issues, but the dialogue in that flashback seems way too verbose and literary to feel real. Something to keep in mind if you make a future project that leans more heavily into happy romance.
Last bit on writing before I move on to plot, theme, and character, I question the use of second person for the narrative in this VN. Usually that works best for VNs with a lot of interaction, where the reader is essentially using the protagonist as an avatar, but I don't think that applies here. This story is deeply personal to Erin, and is accordingly Erin's story, not the reader's, so a first-person or limited third-person perspective could have worked better.
Getting to the meat of the VN, there are two reasons it doesn't quite land for me:
1) The causes for dysfunction in Erin's and Cygnus' relationship feel unbalanced. I think this VN is trying to convey that both partners' mental issues contributed to the relationship's decline, but it feels lopsided. From what we see in the story, Cygnus is consistently trying everything they can to reach Erin, but Erin hardly ever reciprocates. We get one moment where Cygnus appears to cause the problem (sleeping through Erin's day off), but this is immediately cancelled out by Cygnus' expectation that Erin wouldn't be there, which Erin doesn't really have a counter for.
I think a root problem here might be that we learn much less about Erin in comparison to Cygnus. What factors, if any, make him so afraid of commitment? What was his and Cygnus' friendship like when they were just best friends instead of lovers? What brought them together? Why was Erin able to get past his reservations on that first night but apparently not much after that (besides adrenaline and horny)? What was pushing him away during their relationship? Based on how that first flashback was characterized, it feels like there has to be more than just a busy work schedule and playing a lot of Guilty Gear to create that kind of disconnect.
Another angle here could be having Cygnus make more "mistakes". I understand that the intent isn't to make the decline of the relationship anyone's fault, but it kind of feels like Erin's right now. Like, instead of having the Cygnus/Kosta hookup be played for comedy like it is now, have that be more of a betrayal. Ultimately, Erin's absence would still play a role in that situation happening, but it would avoid this issue where Erin seems to be the primary cause of the problem and Cygnus is portrayed as a comparative angel.
2) Erin's catharsis doesn't feel earned. This is the big one. Erin has a line in Cygnus' eulogy that reads: "Cygnus helped me to keep growing and becoming a better version of myself." Uh... did he?
I think it gets swallowed up in the heavy emotions of individual scenes, but Erin's arc actually reads fairly shallow to me. During the flashbacks before we jump into the Black Mirror brand memory plot device, Erin recognizes that Cygnus, while emotionally needy at times, deeply and unconditionally loved him and that he didn't reciprocate those feelings the way Cygnus needed him to. Once we're done with the memory recordings, Erin is reminded that Cygnus, while emotionally needy at times, deeply and unconditionally loved him even though he didn't reciprocate those feelings the way Cygnus needed him to.
You could say that Erin's appreciation for Cygnus is strengthened by those visuals, but to me it almost comes off selfish. The resolution to this whole thing is for Erin to open the drawer and wear the pendant to Cygnus' funeral, proud that Cygnus valued him more than anyone else (yes I know he feels bad about that but still). This reads to me like Cygnus' memories are being used more to assuage Erin's guilt than substantively, materially change his feelings regarding Cygnus.
One potential change you could have made to the ending is having Erin give the pendant to Kosta. This would represent a change in Erin's perspective, from continuing to "possess" Cygnus after their death to giving that memory to someone who was actually there for them in the way they needed someone to be. (Though honestly I agree with Fuze's suggestion that this story would've worked better with Cygnus and Kosta ending up together than Cygnus dead).
Right, so, that was a lot. And I mean a lot. Might be a new record honestly. But there was still a lot to like here, and I don't want the takeaway to be that this was a bad VN. Just wanted to get my thoughts out there, so take or leave them as you will.