Stick of Truth did a great job at fitting a huge amount of memorable characters from 17 seasons of South Park into a single video game. But didn't they forget someone?
Is there any recurring South Park character who does not appear at all in Stick of Truth?
I would consider any character as "recurring" who has a speaking role in more than one South Park episode.
As "appearance in the game" I would count any on-screen depiction - be it in form of an actual character or just a still picture, the character not appearing on-screen but having a spoken line, or the character being mentioned by name in dialog or text.