I'm aware a lot of this is probably gonna be improved on future versions, but I'll just list out my thoughts as if I'm judging this as complete.
Having the option to click to advance text would be neat, as that is how I usually read VNs.
CGs, character design, UI design and atmosphere are all amazing.
Some effects on the presentation of the CGs could be polished, like fade-ins and outs or swipes on the comic-like panels instead them just popping in.
Additionally, audio to go with visuals (either short or longer plapping noises)
Very good dialogue (both main and interaction fluff), mouse sensitivity seems a bit high for me?
Overall this is a fantastic start! Super excited for the rest.