Primer is a very interesting movie centered on the concept of time travel, and the complications that real people might encounter. It is a very low budget movie that managed to do well at the Sundance festival. Usually I hate the types of films that garner awards, as those types are self-important "indie" crap that is joyless and pretentious. Primer is different, though. First of all, it is absolutely awesomely constructed. It's like a puzzle that keeps getting harder as you solve it, and you will be thinking about it after the film is over. As another reviewer said, "anybody who claims [to] fully understand what's going on in Primer after seeing it just once is either a savant or a liar."

Prepare to have your mind fucked. Upon a second viewing, more questions arise as the situation is more complex.

Unfortunately low budget means the cinematography is a little shoddy. There is filter abuse and some of it looks ugly. The acting is sub-par, but some of the cast included everyday people that the director knew. If you don't expect the mechanics to work like a big-budget movie, it won't bother you.