Leaving aside the fact that this movie doesn't make any sense, it is entertaining, has a good plot (if we ignore the fact that it doesn't make sense scientifically), and the protagonist is Jake Gyllenhaal (which is enough). The ending is really nice, and in the end, it's a movie that works, a great product to watch without thinking too much about the inaccuracies it uses to build the plot. These mistakes are scientific, not actual plot holes or directorial errors, so we can accept them. In conclusion, it's a nice movie that would have been really great if it had made sense.