This movie seems to be aimed squarely at me. I'm a 30-something gamer, and this movie pulls obscure references from all over the gaming spectrum. The indie band influences, and hipster joking just add to the meat of the movie.
It's a great adaptation of the quirky 6-book comic set. As with any book to movie adaption, there were some things left out that I missed, but they only have so much time. The comic couldn't have the amazing soundtrack, or crazy visuals that the movie has.
The extras are great, and extensive, from the usual kinds of 'making of', commentaries, bloopers, deleted scenes and such, as well as a short cartoon chronicling one of Scott's highschool flashbacks that didn't make it into the movie. The extras FILL the blueray's free space. Which is a TON.
Having read the comic, I find the casting pretty darn good, except for the two main characters. I have nothing AGAINST either actor... they just don't look like the comics made me think of them. They did a good enough job though. The many musical performance segments in the story are pulled off amazingly.
To mangle a quote from the director, "In a musical, when feelings become too strong, people break into song. In this movie, when feelings get too strong, they break into fights." And fight they do. No bloody brutal fights, crazy impossible funny fights rarely seen in cartoons, let alone in live action.
If you like the movie, do yourself a favor and consider getting the soundtrack, or the books.