Phantom Menace suffers from a lack of focus. Who is the hero? Is it Anakin? Obi-Wan? Qui-Gon? We know that the trilogy is supposed to focus on Anakin Skywalker becoming Darth Vader, but is he really the hero of Phantom Menace? He isn't introduced until a third of the way through the movie. Furthermore, in most classic story construction, the hero undergoes some kind of self-growth overcoming obstacles. In many modern cases, audiences perfer some of these obstacles to psychological (self-doubt, etc.). Anakin never really has the moments in Phantom Menace, nor is he particularly challenged by external obstacles, outside perhaps the pod race. Perhaps Lucas could have gone another route, focusing on Obi-Wan Kenobi, giving him all the emotional heavy-lifting to do, much in the same way J.K. Rowling later relies on her characters of Snape and Dumbledore.
Granted Lucas doesn't have it easy as any attempt to create psychological tension is undermined by the fact that we know Anakin becomes evil. Introducing Anakin as a good little boy who sometimes throws temper tantrums does not help Lucas out either, since it's very difficult for older audiences to accept. It would have been better if Lucas had created an Anakin who tortured cats, pushed Greedo around, loved his mom, was fiercely loyal to his friends, and wanted to be good. At least this would have created some tension for the audience, since we know ultimately he's going to fail. Even Harry Potter wondered if he was evil. These moments start to come out in Attack of the Clones when Anakin kills the Sand People and the new trilogy picks up steam. It's my daughter's favourite one and, at age 5, even she knew what was going on, asking me, "Is this when Anakin joins the dark side?"
