This might be because games are a young medium, but I find a lot of “primers” on game design to feel like subjective reflections of the author’s ludography. The sort of fundamentals a level designer for a 90s first-person shooter would give seem very different from a 2010’s indie platformer dev or a big-budget JRPG producer. There doesn’t seem to be a lot of insight that’s indifferent to genre or team size yet.