This version of Don Quixote, though it carries the subtitle of the novel itself, is based more on the musical "The Man of La Mancha" than on the novel. I admit that no film of the usual length could ever capture the richness and complexity of even Part 1 of the novel (Part 2 being ignored by most interpreters). A mini-series would be required to attempt to do justice to the novel. But the plot line here really aligns more with the musical than the book.
One thing that drove me crazy from the start: The letter "o" in the word "Don" is, throughout, pronounced like the "o" in the first syllable of "Donald", rather than like the "o" in phone. "Don" in Spanish is a title (like "Sir"), not a name. They could at least have pronounced it properly and not thereby announced the American origins of the film linguistically.