Phenomenal visuals and sound design, they do an excellent job of setting the vibe and murder. I also liked the way you wrote each character in the letters -- they all feel distinguished gentlemanly sorts while still having distinct attitudes and opinions. Even though the mystery and means of solving it are pretty simple, I still enjoyed this one quite a bit.
If I had one specific want from the game, though, it'd be the addition of a timer on the screen. But that aside, great work!