YMMV / Pleasant Green Universe

• Continuity Lock-Out: By the end of Shadow Over Innsmouth, this can easily be the case. Without listening to the earlier, pre-Lovecraft stories, listeners would have no idea who Mary Lairre is, what happened to Pleasant Green, or why Parker's name changes so frequently.
• Esoteric Happy Ending: Fugue State ends this way. The protagonists, and possibly the entire village of Pleasant Green itself, have escaped being nuked and Ascended to a Higher Plane of Existence, but it's uncertain just what that existence entails, especially since the ending of Whisperer in Darkness indicates the aliens(?) responsible are connected to the Cthulhu Mythos, and may or may not be the Mi-go.
• Spiritual Adaptation: The stories featuring The Department bear a strong resemblance to Delta Green, albeit with a very self-aware, meta sense of humor. The Mythos miniseries is probably best described as Delta Green with Terry Pratchett as Handler. The similarity gets even stronger in "The Haunter of the Dark", when the Department's opposition within the establishment have them disbanded, forcing them to continue operating off the books.
• Spiritual Successor: Fugue State was one to the original Whisperer in Darkness, involving mysterious recordings and eldritch entities from a newly discovered dwarf planet at the edge of the solar system (Haumea rather than Pluto this time), which was probably a factor in why the subsequent Lovecraft Investigations adaptation diverged so greatly from the source material.
• Will They or Won't They?: Parker suggests that this is the audience's view of the relationship between Kennedy and Matthew. As does Jasper, who refers to Kennedy as "Your girl" when talking to Matthew and jokes about expecting an invite to the wedding... Whether or not it's true is debatable. She also implies there's Unresolved Sexual Tension between Eleanor Peck and Matthew (whose actors are married to each other, by the way). Depending on your view of their relationship, this may also be the case for Parker and Mary Lairre - who has disguised herself as Eleanor Peck, bringing it to a full Love Dodecahedron.