Overall this is a fantastic movie. One reason is: it is complex. There are so many films made for the lowest common denominator audience member now that something that is difficult to follow is almost a treat. I don’t think even the film makers thought anyone could follow all of the plot points the first time through. The time element is probably the most difficult to follow because this is different than anything we have ever seen- this isn’t going forward and backward within our own timeline, it is watching time going in the other direction simultaneously with the people going in real time forward. That is an affect that is very hard to keep up with!
Another element in the mix is the sound because it does make it difficult to understand what is being said at times- yet through all of this I would recommend this film. Just plan on seeing it a second time. At least.