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: The Light Fantastic
Growing the Beard: Pratchett's writing style noticeably evolved from the first book, setting the series on its way to what it later became. The biggest examples are Hrun and Liessa compared to Cohen and Herenna. The former pair parodied stock fantasy roles by playing straight into them, while the latter have clever twists on them.
Death too - less vindictive, more just doing a terribly necessary job.
Death: The death of the warrior and the old man and the little child, this I understand, and I take away the pain and end the suffering.
Jerkass Woobie: Rincewind, who's been acting like a jerk in the previous novel, but here we get more depth into why he is the way he is.
Rincewind: I can't remember all the other spells, they're afraid to be in the same head as you!
Nightmare Fuel: The introduction of the star people is shockingly creepy, dark, and unsettling than the usual quirky villains.
Even Death finds them rather creepy. He can't understand the "death of the mind".