It's certainly one of the most faithful adaptations of a book to screen I've seen. That's not the point of an adaptation. Middling evil.

For a truly misguided literal adaption of a book I suggest "Breakfast of Champions" as it appeared on Showtime with Bruce Willis as the syphilitic car dealer and a special scene of Nick Nolte running down the street in unflattering orange lingerie.

No, tell us how you really feel.

All the wit and humor of Discworld was in the narration.

Strip that out, and you're left with all the flat adaptations.