Robert Pattinson has supposedly called the movie a "slapstick western," but I have a hunch he may have intended something closer to a "western farce." These terms tend to get mixed up because they often coexist. It's common for a farce to contain some slapstick elements as a way of reinforcing the chaotic and unpredictable nature of the genre (or the spirit of the story being told), but Damsel isn't much of a slapstick anything. It's not a Three Stooges western. It is quite silly, clever and violent at times, but at its heart it is a tragedy -- one that is both funny and sad, sometimes within the same scene. And I think that's a big reason why it makes for a very successful farce.
With help from the magical Tilda Swinton, and a physics-defying set piece that is a high-point in the Marvel filmography so far, Doctor Strange has enough style to overcome some weak points in the character department and actually make the 3D surcharge worthwhile.