Primer
And I thought Tenet was confusing.
So generally with movies that are really confusing that don't need to be, I don't like them. But this movie is meant to be watched more than one time. It shows a lot that Shane Carruth trusts the viewer enough to figure it out on their own. Especially with something as crazy as time travel.
This movie sticks with you long after you finish watching it.
It also has some great characterization.
Honestly my main problem is that like 2 shots are morbidly out of focus. And there's an ungodly amount of grain in some of the shots but I mean... The movie was made off of 7,000 dollars. I don't really care.