It's a good story.
As a game:
- There are only a handful of actual choices. I realize that's kind of the "visual novel" style but more agency would be nice (although makes things more complicated)
- There are a number of typos in the text. "apartment" is misspelled frequently.
It's unfortunate that the original artist fell ill (the artist's work is outstanding). I don't think explaining the art style change is necessary, however, in the game's flow. Many adult games have several artists and the other artist managed to match the general "look" of the characters, just interpreted differently.