Give me some more suggested movies to watch like this

Coherence (2013)
Predestination (2014)

One thing they have in common is that you should preferably have no clue about what they're about before you watch them. After watching them, you should be able to see how they are reminiscent of this one.

Don't listen to the negative ones; their arguments are irrational.

Solaris (Clooney version, not original Russian version)

Best unknown feature at IMDB.com
http://www.imdb.com/features/video/browse/

+1 predestination

Memento

The Machinist

What hump? 

+2 Predestination

Most similar to Primer: Coherence, for sure. Also super low-budget, but it's more accessible and thrilling. I think it's a better film.

With a little bigger budget: Looper, Ex Machina, Moon, Donnie Darko

TV show: Black Mirror (it's on Netflix)

Sphere
Coherence - definitely
Skeleton Key
Triangle
Event Horizon
Oculus
Holy Motors - that's more mind-bending, but very interesting. I guess you can say it's a little sci-fi
Being John Malkovich


Trailer for my movie - BEATEN
www.youtube.com/watch?v=CT-TQZbXUVY&featur
on IMDb

First I have to echo Being John Malkovich (1999), Coherence (2013), and Sphere (1998), although only Sphere is science-fiction. Coherence is a many-worlds fantasy indie with excellent acting and almost completely improvised dialogue that feels natural and is never boring. Malkovich is simply the best film ever made, for my money. So yeah, very intelligent, but not really an SF-list. As long as we're playing fast and loose with the term, eXistenZ (1999), Under the Skin (2013), and Trolljegeren (2010) are great fun, well written, well made, but the science is incidental and almost deliberately impossible in each (and why not?).

I thought Solaris (2002) was a great film. It is close to Stanislaw Lem's version in the book and is SF. Tarkovskii's is a departure into psychology/ethereal and while a masterpiece is not SF nor trying to be.

Moon (2009) and District 9 (2009) are both intelligent in their central theme (human resources in the 22nd century and how humans would react to having to take care of another species), but they both have some candy, too (robots and lack of language barrier), and, you know, some people say candy is bad for your teeth.