I loved the visuals and soundtrack in this game because of how soothing they are, and it's amazing that you did all that yourself. The letter ended up feeling bittersweet but hopeful for me (I chose the 'let's break the walls down' option haha, couldn't resist making amends).
I did forget for a bit that this was set in a coffeeshop though, because when playing I kept imagining the protagonist's room, in a house they shared with the letter recipient. It just felt really personal, I think.
Regarding the letter's content, I felt it conveyed a sense of a fairly complicated history between the two individuals, whose relationship hadn't experienced the best levels of openness and authenticity that the letter writer wished for. I dunno if this was intentional, but I couldn't really grasp what the specific events were that had happened between them, so it confused me a bit in the middle of the letter. The ending brought me back though, since I could choose whether to leave or stay.
A really sweet if rather sad story told through a letter. Feels like a journey of growing up and taking responsibility. :')