Game is really good concept, I like how choosing the different routes is more like a game which i feel more visual novel "games" should start doing. So yea keep up the good work on this concept. As for the critique, the endings are a bit bland... even though day 100 it kind of does wrap up a lot of things, but i mean you spend most of your time doing that personality stuff then once you get to the ending it just feel like a ok ending... Also the main character's way of talking and just overall personality is a bit too cringe at times, I get what you were trying to do, but I think in future games you should tone down on that a little. For a side note though, the boyfriend was always very enjoyable I never felt he had bad writing. To be honest, after saying that I can kind of see why you had to make the main character's personality in such a way however because this was more like a dating sim and not soooo much a visual novel game I feel it would have been ok if the main character's personality was just a bit more normal and bland and more just responsive to what the boyfriend says. I don't know..
All in all it wasn't bad at all I really enjoyed the game, but it was just something about the main character's personality that was a bit off putting. I think that if the main character had a sprite then it would have been better since they would end up becoming just a completely separate character in the game.
sorry I hope you can understand my point.