Excellent game. It might be because it aligns so well with my personal tastes, but I'll try to be as objective as possible.
The opening music paired with the looping moon animation creates a very emotional first impression right from the start. Overall, the atmosphere feels incredibly well-crafted, with ambient sounds, a nighttime color palette, footsteps, and many other small details that come together nicely.
The soundtrack is an excellent choice, and the nostalgic feeling of the music, combined with a story told from the perspective of the past and centered around loneliness, is a winning combination. The 3D models are fantastic, and both the character expressions and animations are very well done. The backgrounds occasionally lack a bit of detail, but since they maintain the same natural aesthetic throughout the game and aren't the main focus, it feels more like a technical decision made to fit the time constraints of a game jam.
The story is one of the best I've played so far in this jam. Even though I had already read spoilers for the epilogue and what you intended, it never felt rushed. It's deep, convincing, and provides solid justification for both the characters' actions and the ending.
Interestingly, I had played Reimu and the Fantasy Mirror a few weeks ago. It was fun to discover that you were the author of that game as well. Your progress really shows!