I irrationally abhor a lot of what Animal Crossing is. The aesthetic is really cute and charming, but it's the closest thing to a real work simulator I've played. It is at least partially responsible for making me aware that all game loops are essentially just busy work masquerading as dopamine and cognition sinks.
All of that said, I absolutely love what you've done here. I said all of that negative stuff in preface because what you've done is provided the missing element Nintendo is too afraid to -- other people! The fact that you're sharing these anonymous notes with other people is incredibly charming and it's what Animal Crossing desperately needed.
This looks incredibly slick too. Your design skills are top notch!
(The fact that Animal Crossing asks you to write letters to the dumbest NPC AI and gives you occasional token rewards is downright depressing. It's cookie clicker level stuff.)