The most perplexing thing about Green Lantern: Emerald Knigths is the choice to depict Sinestro as still one of the good guys. Most people who aren’t into comics and only saw the previous animated Green Lantern movie First Flight, will probably be a bit confused by this. But then, this is not a sequel, but a sidequel to the recent life-action version of Green Lantern (since I’ve not seen it, I assume from the trailer that this one also depicts Sinestro as a good guy the whole running time).
Like Batman: Gotham Knights (the sidequel to The Dark Knight), GL:EK has a similar anthological approach, but feels more cohesive both due to the frame story and the sameness of the visuals. It’s one of these things where the whole is more than its parts. Individually most of these stories aren’t all that overwhelming, but taken together and with the overall frame story, it gives you a very good idea of what the Green Lantern Corps is about. This isn’t so much a Hal Jordan movie, but a Green Lantern Corps one.
Where the movie really owns is in its final fight sequence, where all the Green Lanterns stand up to the entity Krona. From time to time I ask myself why I’m still reading superhero comics (or watching superhero movies), but then you’ll get something insane like a gigantic humanoid entity birthing from a star and trying to destroy everything in its path, and an interstellar police force with will-driven power rings stops him by throwing a planet at it. It’s ridiculous, but also incredibly fun when well done, as is the case with GL:EK.