I've never read/played a visual novel and I'm happy that this one was my first.
The story is interesting and engaging. I do think the writing could be a lil better but I'm also quite harsh in my expectations towards stories/writing and this one did catch and keep my interest which is really all you need for it to be fun.
The design of the UI was clear and the design fits the story. The sizes of the menu buttons during gameplay are a lil small though.
The choice to make the visuals based on how the prota sees the world does make the story more engaging and adds to the athmosphere of the story.
I do wish that the end points where explained in some way that is understandable without asking for clarification.
The sound effects sometimes underline the story nicely (the cannon shot gave me half a heart attack though)
All in all it is a fun read and good starting point for something really good