"Secondhand Lions" is a movie which has achieved excellence. The story line is fast-moving and packed with nuance. Various elements of the plot overlap and blend for a harmonious whole. It is not a series of action scenes played primarily for visual impact, but a compelling story which demands attentive viewing.
Flashback scenes are intentionally cartoonish, so that the audience, like the character of the boy Walter, is left wondering whether the fantastic tales of the old uncles' adventurous youth are really to be believed. Uncle Garth tells the stories, which we see through Walter's imagination. We see in the flashbacks what Walter envisions as he hears the stories, and Walter doesn't have the age and experience to see anything other than the caricatures which appear in the flashback scenes. It's not a photo-accurate rendition, it's what a youngster imagines while listening to oral storytelling. For instance, a twelve-year-old Texan in the 1950s wouldn't have been likely to know what a really angry Sheik would have looked like in the 1920s. These flashbacks, and the ways in which they are depicted, are central to the plot of the movie. Through his storytelling, without realizing it, Uncle Garth nurtures a creative potential in Walter (who will grow up to become a cartoonist).
Christian Kane is a magnificent casting choice as young Uncle Hub (the younger incarnation of Duvall's character), displaying just the right kind of spark for the daring adventurer. Kyra Sedgwick is eerily believable as Walter's shallow and self-absorbed mother. The family of hick relatives is superbly annoying.
Haley Joel Osment delivers a solid portrayal of Walter. Sometimes his voice sounds like that of a boy, sometimes like that of a young man, as would be expected in a male of Walter's age. Sometimes Walter cries like a child, sometimes he displays stoic maturity, as would be expected from a boy who is in the transition of becoming a man. We see Walter unsure of himself in the beginning, but later finding his footing. Not too sugary, not too hard-edged, Haley Joel Osment is ideal for the role. He may be overshadowed by Caine and Duvall, but actually holds his own reasonably well, working between these two living legends.
Michael Caine's accent as Uncle Garth is a perfect portrayal of a Texan who has lived outside Texas for much of his life. Garth is no bumpkin hick, but a man who has traveled the world, and in light of his experiences it would not have been credible to give this character a strong country drawl. Even though, as the plot progresses, we don't know how much of Garth's fantastic storytelling we should believe, there is never a question of whether Garth has ventured outside the Texas borders. (Education and travel tend to have the effect of diminishing regional accents. I have lived in Texas for twenty years, and have known many older native Texans whose diction is much like Garth's.) Michael Caine gives Uncle Garth just the right combination of toughness and tenderness, and treads the fine line of allowing us to see Garth as a trustworthy character regardless of his adventurous stories.
The uncles are very realistic characterizations, and Texas holds many characters like them. The aging uncles had, as young men, gone away to find adventure, and lived on the edge for much of their lives. Then they returned home to retire in a rural Texas setting which they were finding to be just a little too tame, no longer remembering much about Texas country life except for acquiring the obligatory too many dogs. The uncles don't say much to each other because there is no need to say much, they understand each other perfectly. Confronted with age, they seek out reckless behavior, unwilling to sit still and get older, unable to overtly give up on life. Walter's presence suddenly requires them to adapt to new purpose, and to take care of themselves, too, as they are faced with the issue of providing appropriate male role models so that their young nephew might one day become an appropriate man.
Despite the studio's description, this is not a "heartwarming" movie with a happy, fluffy resolution for all concerned. The characters must make choices, and not always easy ones. The valiant tales of adventure don't always conclude with happily-ever-after fairytale endings. It is not purely a comedy, but instead probes the depths of emotion. The adult audience will probably appreciate this movie the most, but it is an appropriate movie for pre-teens as well.