Woah Neat!
I love the feel and style of this, but it's so good I don't have much constructive feedback :v.
1. I think you should move the dialogue text to take up more room in the box, you should move the speaker text up and to the left a bit, maybe in it's own box with a separate font or even stylized box.
2. You should move the little setting text bits up a tad so it's not in the border of the box.
3. I think the background image is a bit stretched, the clocks were sorta ovals to me.
4. There's some read-mes and other files floating around your final build. (Which is interesting to dig around). I'm not sure how most VNs do it, but .avi videos for the CG scenes seem pretty storage heavy, the train scene was 10mb alone. Some audio clips are in .mp3 and some are in .wav
5. The starting volume seems a bit too loud, I found about 50-60% was good for me using a headset.
I didn't mess with much of the settings, or save feature. It took me about 20 minutes for the 2 chapters and coco's special chapter.