Holy shit, oh my lord this is so good! The endings, they hit HARD! They're well done and I love the plot and its mysteries! Despite the awkward grammar, it made me read it out loud to bring out my own twist and it gave the good effect of immersion because each scare surprised the hell out of me! I like our dear MC, she gives your typical "new person" and pretty naive and sincere, a classic MC, but I love how she keeps a levelled head when it's time to get serious. But Ghost, man I love him in the endings, I adored the way he lost his mask at the ending and how insane, delusional, and so clearly inhumane he is when it's finally time to reveal to MC who he (or well, it) is. The way his dialogue flowed was really cool because you get the clear feeling that "Oh, this guy? This guys is fucked up". Also, yandere with multiple darlings??? Sign me the fuck up! I absolutely love it and I only see this in Tumblr and even that is a minority! Just, the way Ghost professed his love to all 5 of them (6 including MC) was just so raw and corrupted, I absolutely loved it!
SPOILER BELOW! Despite how much I love it (seriously, I love all the endings), there are some parts I find could work a bit more, especially when it's a lil mystery (I say this as I played mystery games and fried my brains over puzzles and having to resort to hints and playthroughs...).
I think spacing out the days more evenly would work well, especially for the first part of the visual novel which is the Investigation Portion where MC has to figure out the 5 Missing People's Case (had to rephrase that cause it was just awkward grammar wise, but other than that it's okay!), it would have been fun to interact more with the case itself to uncover clues and witnesses and seeing the connections between the victims and Ghost (why exactly did Ghost target those people and the consequences of him taking them away) so MC and us players have something more concrete going on as to why Ghost targeted those people.
While us players already know that Ghost is the murderer, MC doesn't and in that time you could show exactly why MC chose to go to being a detective. And in that investigation period you could be able to establish not only MC's bond with Ghost to be more stable and to make it so that MC can't believe Ghost did it but show enough of MC's personality and background to prove her convictions, but also to establish Ghost's inhuman aspects.
Just like in Bad Ending: I trusted... who? with Ghost erasing his existence and leaving only MC to remember him. It would be more cathartic if MC ran towards other office people demanding them to know about Ghost, running out of the office to the cafe to the waitress, and anyone who Ghost and MC interacted with just so MC can prove that Ghost actually existed, all while Ghost taunts MC from her mind driving her insane.
In True Ending: Please, it would be nice if the features Ghost took from them could be reflected as we investigate, I feel as though it was redundant to have Hayden's eyes be taken out only to have MC's eyes replaced in, and Tim wasn't bald like Olivia even though Ghost used both of their hair, maybe Tim could have been bald like Olivia but be as brainwashed as Giselle and Hayden would have lost his tongue instead. That and Giselle losing her kidney is a bit weird as we can't see it from Ghost's appearances, maybe she would have lost her teeth to Ghost as in she lost her smile cause in the photo she was smiling brightly. Other than that, the entire segment of True Ending is horrific, especially poor Sam like dude lost his skin. Even it being chibi-fied it was horrific.
And lastly in Good Ending: Sweetheart, it may have been nice to see Ghost lose all of the features and clothes that came from the Giselle, Hayde, Olivia, Sam, and Tim, maybe even lose his own name. I say that because MC makes it a point to say how only she is special to Ghost and as such, he should let them go and only have her as that was the deal. So for Ghost to lose all of that which is his identity would just show how he utterly loves MC. That and I would have loved to see an after story of the after effects of the 5 of the people who went missing, particularly on Olivia who was the keenest to get revenge.
Aaaaaa I rambled for so long but goddamn I absolutely love this visual novel! It's really impressive for it to be your first game! I'm really looking forward to see what else your mind can conjure, have a great day/night~!