A strange little side quest
Letter Mix may feel immediate, but the ideas around puzzles have been evolving for a very long time. The first crossword puzzle book appeared in 1924 in a cautious initial printing of 3,600 copies, complete with a free pencil. There is another connection worth keeping in the same mental pocket: Spacewar! appeared on MIT's PDP-1 in 1962 and became one of the earliest influential computer games shared among programmers. Not bad for a few facts hiding behind a Play button.
