I think the graphics are great and it's a good concept, I think you can take this way further and have a full visual shop, different types of paper for the letters, different visual cues for the dialogs or audio cues. I think also the ui could use some tweaking so many times there was like overlaying text that was competing with each other I didn't always know exactly what I should be looking at.
I wanna edit this by saying, I usually take my reviews/ ratings seriously as opportunities to find flaws. So sometimes I might come across as nitpicky or something- but I think these jams are an opportunity to everyone including myself to make better and better things. I am specifically editing this comment cause I wanna say I really genuinely loved your vision here and look forward to seeing what you make in the future.