Primer (2004)

Made on the absurdly low budget of $7,000 (!), this is a cerebral, technically focused take on the time-travel mind-bender, in which two engineers working on a side project in their garage find that they’ve accidentally built a device that reverses time inside of it. The plot is often (intentionally) incomprehensible, and it’s by no means interested in neatly resolving or explaining everything that happens, but there’s nothing else quite like it.