I watched it a few weeks ago on a friend's suggestion. He saw I liked Slaghterhouse 5 and told me I'd like this one as well.
Like you, I thought it was good but not overly mind bending. I liked the theory behind it and the story was good. My main concern was the fact that they spent so much on trying to be heroes in one area and complete slime in another.
I don't want to give anything away, hence the ambiguity but I really did like it. It had a very well thought out premise and and the take on it was realistic.
I haven't seen his other movie yet but the same friend said it is good to. It's is also on Netflix and called Upstream Color.