Blankments’s review published on Letterboxd:
Klaus is gorgeously animated while being full of Christmas magic. With that said, compared to every other new Christmas movie I saw this year, it's wonderfully competent at actually being a movie as well. It tells a clever story, reworking the usual "Santa's origins" angle with a true heart, although with a somewhat generic structure.
Nearly all complaints about the film fall apart when seeing it in motion. This is truly some of the most beautiful traditional animation in decades, revisiting the classical Disney style but enthused with a modernity that never feels insulting or forced. It's simply delightful to look at, and with the voice actors melting into their roles and the story being a bundle of charms, it's a film that feels like the biggest Christmas miracle of them all.
Sure, the third act falls into cliche, and there are more than a couple moments when the film feels the need to be ultra-modern, but all this is forgiven in the moment. Klaus transcends its obviously flaws from its technical mastery and emotional resonance, being the first true modern Christmas classic in many years. Absolutely lovely.