After thinking about the 20 minutes or so I think needed to be added to the movie to really connect everything together (and they could drop at least 10 minutes that was on screen) to make a top tier story, I wonder if the issue was budget. 1. The training, Sinestro and most of the corp having low expectations of Hal should have been at least 5 minutes longer. He literally had 5 minutes training and then quit? It should have been done to indicate he was gone at least 3 to 4 weeks and more interaction between Hal and the other GLs showing he was poorly regarded but he had some human trait that gave him an advantage over the other GLs if he could just tap into it. Otherwise it is like Luke defeating the Emperor in ESB after the few weeks with Yoda on Dagoba. Plus when you quit the police department you don't get to keep your badge and gun. 2. Parallax destroying the two other worlds and killing 3 other GLs needed to be shown. Movie Rule 1: It it doesn't happen on screen, it didn't happen. Needed 3-4 minutes to actually show it instead of telling. 3. The big fight between the 7 GLs and Parallax the first time. Needed another minute. 4. More time needed to be spent showing that Sinestro became disillusioned with the Guardians and the power of will after being wiped out by Parallax and yellow energy, when he previously was an absolute true believer. There is a kernel of a really believable reason why Sinestro wanted the one ring, I mean the yellow energy ring for himself but they needed to show more of the transformation and his desire to control what he thinks is the most powerful energy in the universe. Plus if they spent some time and played up the fact that Sinestro was the number 1 GL right up until Hal Jordan, a human newbie, beat Parallax by himself so maybe Sinestro isn't quite the leader and as powerful as they all thought he was and jealousy could have been an additional factor. Obviously Hal Jordan could control green energy better so maybe yellow energy would give Sinestro the edge he needed. Show it please. As it is shown, Sinestro's faith in the power of will should have been restored by Hal Jordan so his taking the ring makes no sense. 5. The final fight between Hal and Parallax needed at least 5 more minutes. Everyone of those extensions are pretty easy to write and were probably in the original script but they are all full screen CGI scenes and I'm sure cost a bundle. It seems like they had an outline of a good story, filled in many of connections between each bullet point and then said "Stop. We have no more budget to fill in any more. The audience can fill in the missing scenes themselves." Maybe Green Lantern is still just too expensive to do live action and create the GL Corp universe for the entire movie.