The official Star Wars website has a very neat post comparing the comic adaptation of the movie by Marvel (1977 to 1986 series) to that done in Japanese manga style by Media Works (1997 - I believe these are created by Tamaki Hisao, published in English by Dark Horse comics).
When the two are placed side by side, the contrast couldn't be greater. Take, for instance, the battle between Luke Skywalker and Darth Vader in Episode V: The Empire Strikes Back. The manga version showed the gruesome scene in two-page spread. Marvel, on the other hand, were forced to tone down the visual by hiding the action behind a "convenient scenery."
The manga version
The Marvel version
Check out the entire article here: http://www.starwars.com/eu/lit/comics/f20080227/index.html
But I was bummed to find that the article's writer didn't show us pics of Vader's sans-helmet manga face. The article stopped just shy of the Big Reveal. AARGH!!
--TwoDragons
As for spending so much time on Alderaan exploding, perhaps that sort of destruction unleashed has more impact on a Japanese audience, considering WWII.
http://www.theforce.net/humor/jaxxon/jaxxon-04.asp
http://www.theforce.net/image_popup/image_popup_global.asp?image=humor/jaxxon/pics/jaxxon_18.jpg
Enjoy.