These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Nation
Complete Monster: First Mate Cox, perhaps Pratchett's best example of this trope
Continuity Porn: Daphne explaining Nation's history to her dad at the end.
Squick: Pig. Milk. Specifically, what Mau had to do to get the pig's milk, namely cover himself in stinking mud, wriggle close to a sow (which he'd gotten drunk with beer-laced vegetables), and then put his mouth to the sow's muddy, stinking belly and suck out mouthfuls of milk, because pigs don't have udders you can milk by hand.
Doubles as a Crowning Moment of Awesome for Mau, because he was perfectly aware all the time just how disgusting the act was... and he still did it, because the alternative was having an innocent baby starve to death.
Tear Jerker: Lots. Especially Daphne and the coffin memories (which are somehow edited by Mrs. Gurgle).
The Woobie: Mau. He starts off with his whole tribe dying in a tidal wave, after which he goes BSOD while preparing the bodies for dolphinhood. He almost drowns himself. He almost drowns himself again while saving Daphne. After this, his catchphrase/Survival Mantra becomes "Does Not Happen", and he proceeds to become the Badass leader of the emerging tribe. It is stated by other characters that he works himself too hard and doesn't eat or sleep (which nearly kills him), because he's that goddamn traumatised.
At night he guards the Nation by standing on the beach with a spear. Who is he expecting? The freaking god of death.