Biggest thing that went against this film is the lack of scenes where Green Lantern actually shows him power. It was off to a very slow start, and the set-up of the plot took most of the film, which was annoying and boring. The humour was tired and worn, the film lacked charm. The brief training session felt over-reliant on special effects, which can be said for the film overall. It wouldn't be so bad if it was well done but it felt really cheesy and floaty. The climax was disappointing and even moreso when you see how the antagonist was destroyed. For such a powerful being that can wipe out entire civilisations and multiple members of the Green Lantern Corps at once, who knew his weakest was such a simple affair. You would have expected this to have been exploited already before since he would have passed many different (and probably bigger) stars during the antagonist's travels (and there is nothing special about the sun). So this means that the 'epic' final battle felt cheap, brief and not worth the time it took to get there. The post-credits scene was also straying into the cliche area and offers no surprises, it's setting up for a sequel but... there isn't one announced as of yet (this situation is always the worse when you try and set up for a sequel but it didn't end up making enough money to warrant one).