Cloud Atlas is loud, confusing, awkward, painfully earnest, and a lot of fun. The best way I can explain it is take a half dozen really good trailers for movies you would normally not bother seeing, draw together some obvious thematic parallels and let the trailers find their own way towards a coherent movie. It's like a movie created only from the 'good parts' if by 'good parts' we extend our meaning to include the necessary quiet sections of introspection and character development that appear in trailers right before the music swells and the marquee actors names flash on the screen.
If you don't know much about this movie or the book from which it is adapted, then here's the short version: six stories, taken from a variety of time periods and genres, weave in and out of each other's story lines, the characters from each story in someway influencing or informing the characters of the next. In the movie this idea is reinforced by the gimmick of having the same actor play a variety of roles throughout the movie. Hugo Weaving appears regularly as a face (and voice) of menace. Halle Berry alternates between various heroines and side-characters. Tom Hanks chews up a great deal of pre- and post- industrial scenery.
Rather than picking apart each story, I'd say you need to use use a wider lens to capture what is special about this movie. While none of the stories (with possible exception of the Cavendish misadventure in a geriatric home and the oddly fashioned post-apocalyptic yarn with Zachary (Tom Hanks)), fully registers by itself, the movie builds considerable power by showing how the themes of the movie: power as an act of consumption, freedom as boundary transgression and order as confining tribalism, echo throughout the ages. I found it easy to forgive a movie this ambitious for many of its flaws because I felt the overall vision was interesting.
Don't get me wrong. This is not a great movie. When I say flaws, I am talking about clunky dialogues (something that mars just about every section of the film), pointless action set-pieces (mostly in the Neo Seoul section), and overly pat resolutions (again, most of the sections). I don't mind happy endings, but I dislike it when the hero always gets the last word. Cloud Atlas the novel (which I'll be reviewing in the next week or so) never confuses moral judgements with the necessities of plotting. Cloud Atlas the movie keeps toeing up to the edge of grappling with the despair of the stories before flinching. If the ending is not always happy, it always allows for some moment of catharsis and healing and hope. I think a little more despair could have gone a a long way to making the final few minutes of the film seem more earned.