* Amara endures a number of depressing incidents in "[[http://www.platypuscomix.net/keiki/index.php?issue=5&pageType=index&seriesID=5 Freewheeling]]", especially when she discovers that [[spoiler: the time she became a popular trendsetter was AllJustADream]]. Peter boasts in the ''Keiki'' archive that people called this the best comic he made up to that point, but doesn't explicitly say why.
* Darcy's [[http://www.platypuscomix.net/keiki/index.php?issue=14&page=21 rant]] about the media's romanticization of vampires in "Twilight Princess" includes a lament about the fact she can never have a romantic relationship with the [[MayflyDecemberRomance mortal]] Beefer.
* Arguably, the part of "Princess Pi vs. The Totally Nazis" when the Totally Nazis' [[http://www.platypuscomix.net/princesspi/index.php?issue=3&page=6 ceaseless insults]] appear to [[http://www.platypuscomix.net/princesspi/index.php?issue=3&page=7 push Pi]] over the DespairEventHorizon.
* "Princess Pi vs. CerebusSyndrome" plays most of Pi's overly grim stories [[PlayedForLaughs for laughs]], but the story of [[http://www.platypuscomix.net/princesspi/index.php?issue=11&page=8 the death of her mother]] feels genuinely sad.
* See TearJerker.TrueBelievers
* Peter Paltridge's unending suffering in "[[http://www.platypuscomix.net/history/kellogg.html Kellogg Middle School: The Happiest Place on Earth]]".
* The "Concept Unification" video in "[[http://www.platypuscomix.net/kidzone/chucke.html The Chuck E. Cheese Story]]", detailing the transformation of a Showtime Pizza restaurant into a Chuck E. Cheese facility, includes a warning not to watch it because "it's too depressing".