Do you ever watch a movie and sit there, staring at the credits, pretty sure that you missed something? And then, as you talk it over with the other people who watched it with you, you start to realize that none of them, intelligent as they are, caught that it. And then, as the conversation drifts out of discussions about camera angles and lighting, you realize, no, we all did not in fact miss something. It wasn't there in the first place.
That's Primer. Primer is one of those films that was shot so cheaply, you want to believe that there's something meaningful there, something that made it drift onto your list of movies to see. But at it's heart, Primer is the same story you've read about time travel and maintaining the purity of the flow of time, only so convoluted and devoid of direction, you have to fill in the gaps with made up story in order to have the movie make sense.
The clever part of the story is that one of the time travelers wakes the beast in all of us, the beast that realizes that by using the time machine, he can improve the present for himself. But the morality tale of what becomes of family, friends, and self gets lost in the self. The characters are simple until the last, when Aaron (played by the director, Shane Carruth), wings his way out of his life in the present to a world in which he is now prescient of that which will happen (thanks to an alluded-to trick of time travel). No regret, no thought about his wife and child, no connection to his friend Abe, the man who basically handed this new world over to Aaron. Abe is able to completely eschew all aspects of his past life and jump, happily, into a new existence. The complete disregard for any normal, human emotion is as ridiculous as the "science" that leads to the machine's creation.
This movie, for all it's appearances, is not Pi (that would be the other movie shot on under $10K that made it big). Pi had an engaging story, characters you hated or cared about, but at least felt something for, and acting. Primer is a study in misdirection and filmographic minimalism, but not entertaining or deep. It's perfect fodder for the indie circuit, however, so get ready for lots of gushing from people who are pretty sure it means something, but can't tell you what.