This was a cute game. I like how it included a handful of bonus puzzles outside of the main story. Making Cassia an airhead like this really enabled Senna's character in a way that I found fun. Also, interesting to know that you did all the music yourself. Since it was noted that you don't really listen to Lo-Fi casually, that explains how it came out a bit closer to what I'd expect to hear in some chill lounge rather than an anime girl studying for a test.
I will say that the story 15x15 is equal parts easier than it was made out to be and really fun to draw, since it has an outline that can be drawn without lifting the "pen", so to speak. This means that once it clicks what the numbers are hinting at, then the player can glide through most of the puzzle. For a final boss, that's pretty clever, and since it's the only 15x15 in the story that doesn't diminish what I view as a low difficulty 15x15. Plus the final post-game puzzle was in line with my personal skill level, so I got to have my cake and eat it without getting a player less used to picross than me stuck on the final level.
As a final note, I didn't know you could make picross in RenPy. I'm super curious what it was like making a puzzle game in what most people view as a VN engine.