Wowowow, loved this a lot! The art style was really fresh and well done, and the story was definitely really intriguing, a super fun fake-out in the middle.
I have a few nitpicks for you, though these are so minor, they haven't had any bearing on my rating (if you know what i'm 5aying).
I'm not sure of the capabilities of your engine, but I really really recommend changing the font -- your beautiful visuals deserve more than Verdana!! Nothing too kitsch, just something that understatedly matches the vibe of the game, (a brief look on Google Fonts, maybe something like 'Quicksand'?). It will really take your game from looking like somebody's pet project, into a bona fide, professional and artistic visual novel. Furthermore, using different fonts (if possible) for just the different character names can instantly help the reader more clearly and instinctually understand who is talking, esp for people with CVD or reading processing impairments.
Secondly, your writing is definitely solid, the characters are fun, but I'd love to see them pushed beyond just being 'the peppy one', or 'the moody one', or 'the arcane one'. Your visual character design is just so unique and original, but personality-wise, I feel like I've seen already these characters before, y'know? So just pushing, developing the characters further, making them kinda weirder, really, and trying to pull away from the cliches of character writing. Kind of hand-wavy feedback, but just a direction for to consider working on.
Anyway, fussing about aside, I super loved this, you did absolutely fantastic.