If you have any sort of understanding of how time travel (theoretically) actually works – avoid this film. Not because it’s mind bendingly complicated, but because it’s mind bendingly stupid. The characters are dry and unlikable, the plot is riddled with holes. Joseph Gordon Levitt looks like a train ran over his face. Predictable ending – which is a shame as the writers could have gone just about anywhere with this one. So many missed opportunities to make a clever, well thought out film that you makes think.
Incidentally, if you want something mind bending with a splash of horrific frightening, try The Triangle.