The movie seems to be able to be somewhat enjoyable throughout. It's not really a mystery, but it has an interesting enough series of plot twists and turns that keep things entertaining throughout regardless. It was at least adequately entertaining for the most part.

It's very rare that a movies ending manages to genuinely severely hinder the rest of the movie.

Glass onion is not fantastic to begin with, but the ending was so utterly atrocious and insulting that it managed to nearly ruin what good the rest of the movie had going for it. I could not believe what I was seeing, and not in any good kind of way.