This film, like IMDB says, is a "coming of age story", but it is wonderfully eccentric as well. In short, two old brothers live on a delapidated farm in Texas, and their great-nephew is left with them for the Summer by his rather inadequate mother. The uncles (played by Robert Duvall and Michael Caine) become reputed to have a fortune stashed, and this brings travelling salesmen and relatives who are seen off by the shotgun-weilding brothers.
The brothers soften and the boy strengthens as characters do in this style of tale. The plot contains a great deal of happenings. It is about people, worthy and unworthy, decieving and forthright, strong and weak, but it is also about life and how to live it as well. It is a lesson (or perhaps a refresher course) that everyone should take regularly.
The film has a feel of "profundity tritely delivered", such as you find in works by Peter Carey, with a dash of "The Prince of Tides" for good measure. The humour is uncommonly quiet and subtle for an American film, especially one set in Texas.
As a final note, most of the story is a flashback that starts 10 seconds into the movie; the present, when you get back to it, is cute, and the delivery of the credits very imaginative.
http://www.imdb.com/title/tt0327137/