Not a great piece of art (it won’t change the way you look at the world), but excellent entertainment.
The story, such as it is, involves a guy whose job is to steal ideas from (or, sometimes, insert ideas into) someone else’s subconscious, through the use of carefully constructed dreamscapes. That’s pretty much all you get — this is fantasy, not sci fi. But following the rule of all good fantasy, the story generally stays true to its own rules. It helps immensely Christopher Nolan both wrote and directed the film, which means that by definition the writer and the director share the same vision. And the movie is free from those logical jumps that indicate script doctors at work.
Leonardo diCaprio is famous for his intense preparation. It really pays off here, where he creates a believable figure out of an essentially fantastical premise. The supporting cast, largely composed of actors who have carried other films, is particularly strong — Marion Cotillard, Ellen Page, Ken Watanabe, and that guy who plays Leo’s father (not credited, so I won’t spoil the surprise).
Some of the reviews have complained that the story is hard to follow. My suggestion — think of it as a video game. Just remember which level you’re on, and don’t worry too much about whose brain you’re in. It’s a shared experience.
The film is full of little references to some of the actors’ prior movies. What shipwreck is Leo crawling out of the water from, exactly? And there’s Edith Piaf warbling in the distance. It’s almost as if Nolan wants to remind us that movies, too, are a shared dreamscape. As one of the characters notes, “Just draw in the outlines — your subjects will fill in the rest. And they won’t notice the stuff that’s missing until they wake up.” Indeed.