I got to play Dialect at IndieCON, although only one of the three phases of play, so these thoughts are certainly tentative. I haven't read the rules either.
"It's the game about the rise and fall of a language!" True as far as it goes, but that's a stalking horse, good at drawing people in out of interest - one step short of a gimmick, given that the content thereof is real and important, but definitely not "what it's about." If it said what it's about, no one would play.
Some of the points I'd like to make are better reserved for more private space, which in this case I will designate as the patrons (with acknowledged self-interest). As I hint in the video, I have insider knowledge of more than one community of the type that the game is about, and also of the greyer boundary-almost communities which were extremely common in the U.S. I was never a "cult member" in the ordinary sense of the term, but ... well, anyway - I'll put up a video at the Patreon, in a little while.
Not much to say here that I didn't in the video, but attached is my brief list of concepts and terms that we used in play.