Hello! Welcome to Feedback Quest 8! My name's Hythrain, a co-host and one of the streamers for this event! This feedback is being written live as I stream your game! If you're interested in seeing my live reaction, let me know and I can send you a link to the VOD once it's posted to YouTube!
So my normal approach for any game in these events is simple: I get the game, make sure it's not a virus, then play it with as little information on how to play as possible. This way, I can judge how intuitively someone can figure out the game. Only if it's obvious that I need to read more will I do so. I note this so you can get a sense where some of these feedback comes from. In addition, I want to note that feedback and rating are different; don't use this feedback to gauge what I'll rate, nor should you view my rating as entirely indicative of my feedback.
So this demo was incredibly short, but there are already a lot of things I can say about it. Before I get into it all, I want to note that I often find games like this cause strong emotional reactions in me. As such, I tend to care more about these sorts of games to the point where I nitpick at a lot of small things. While a lot of what I'm about to say may come off as negative, I want it know it's because I want to see this game reach its full potential. I'm also not going to give a typical breakdown of "visuals, sound and gameplay" since this is all about the narrative experience, though the visuals are gorgeous and I like the choice of music. Instead, I'm going to focus on specific things that I feel should be addressed.
First, let's talk the camera. While I'm not 100% certain of this, I believe the camera is making use of something like "mouse acceleration." The camera moves very fast and can whip around. It also has a strong bounce to it. While this effect can look cool, it can also cause some people issues. I would recommend making this a controllable setting that players can adjust to their liking, including turning it off entirely. Otherwise, the whiplash from moving the camera around can be a large detriment to the game.
Next, I would advise AGAINST doing auto-dialogue, where players need to sit and wait through. Instead, players should be able to click to proceed the dialogue. That way, if they have a distraction they don't miss anything vital. Similarly, they don't need to sit around and wait when they've already read what's on screen. I would also say that cutscenes should be skippable. There are a lot of ways to do this, but if you need suggestions on what method may work best for your game then let me know and I'll think it through.
While the game looks pretty, there are absolutely things that need to be done regarding the graphics. Allowing players to change settings is a good idea, since not everyone has a top-of-the-line computer. In a similar vein, there should be some passes to optimize the graphics to reduce how much resources the game uses. There also needs to be some improvements to the UI. Having dialogue appear in an awkward black box just doesn't look good. If you already have this mind, then ignore me.
The last thing I want to cover is the narrative. There are a few things here to say, but before I get into it I must note that I'm unfamiliar with your background. As such, if any of the things I bring up are related to, say, English not being your native language, then consider what I bring up as me just trying to help you clean that up. So first, I caught some awkward sentences and misspellings. If you interact with the door to the shrine on the way to the Flower Forest, it says "The shrine is not open this time of the week." However, this sentence just doesn't work. If it was "this time of the day" it would be fine. What I think you wanted to say was "The shrine is not open this day of the week" or "The shrine is not open today." When talking with the Monkey, the word "caught" is spelled wrong as well.
Despite all this, there are still two things in the narrative that really bother me. First is that the protagonist decides to just go to the Flower Forest because they found a note with their name on it after they were just mourning at her grandmother's grave. Her choosing to go along with this is just unrealistic. I get wanting to move the story forward, but you're better off taking your time. It would make more sense for Rei to assume the letter is a prank and ignore it but things keep happening that push her to go to the Flower Forest. This was, it comes off as more natural.
The second thing that bothered me... well, consider this going back to my "I don't know your background" part. While I know Japanese culture is more accepted in other parts of the world, I don't feel like this should be a Japanese character story. This story is based around the Jade Emperor and the Chinese Zodiac. As such, it would be far more appropriate to be a Chinese character story. Now granted, many Asian cultures still make use of the Jade Emperor and the Chinese Zodiac so there can be precedent for it being about a Japanese character. However, if you're going in this direction then I would advise ensuring that Japanese theming is prevalent in the story. This would obviously take some research into Japanese culture and how the Chinese Zodiac and the Jade Emperor are viewed in that culture. Doing this, you can make your story feel more authentic.