I loved the concept but could not for the life of me figure out how to get any of the other endings. I tried a few things but that turned the game into a never-ending menial task of sorting without any progression, so at some point I was not motivated anymore.
However, I love ending #1 and the whole concept is super neat. I do wonder, though, if this could be even better if we were to read a few letters that hint at what actually is going on. Add some lore and realism because let’s be honest, we all would take a peak at the letters :D