Shane Carruth, who does almost every job on this ultra-low-budget film, delivers enthralling and infuriating in almost equal doses — but this has its own distinctive pace, look, sound and identity, so that’s the price you pay.
Even though our two leads take extra caution not to create paradoxes, our two heros still get caught up in a tangle of doppelgängers and multiply-erased events. It’s a puzzle as much as a plot, but when it’s in focus (which it isn’t for long stretches) it’s remarkable brain-food.