Sword Art Online is an adaptation of the LN series by Reki Kawahara, author of the Accel World series. The anime series adapts the first 4 novels, covering the Aincrad and Fairy Dance (Alfheim) story arcs, as well as several of the short stories.
Story - 7.3/10
Set in the near future, the story revolves around the main character Kirito and the world of Virtual Reality Gaming. A gaming junkie's paradise story setting but sadly it falters in several key areas.
First and foremost though, the fact that it changes games halfway through the series shouldn't be held against it. If you knew how the LNs were structured then it should have been obvious that this would happen. And the Alfheim story arc was still good and worthy of praise, even if it wasn't the classic, definitive MMORPG world that Aincrad was.
However, both the Aincrad and Alfheim arcs ended poorly. In my experience, this is something that the author struggles with. He doesn't know how to end storylines in an effective manner and they often end in bizarre, ridiculous or disappointing ways. The fact that this happens twice in the series reflects poorly on the show as a whole, but probably matters less than if the show was 2x12 episode series as opposed to 1x25 episode series.
Secondly, the requirement for the short stories as filler was highly detracting. Especially since they come in right after the opening 2 episodes. Stopping the storyline in its tracks like that stunted the flow of the series.
Finally, because of the nature of the series the show skips chunks of time, especially early on. You don't see the cast walk through level after level. Essentially, the show skips all the "grinding" aspect of the game and hops to times relevant to extending the storyline of the show. Whilst this isn't really an issue as such, because the nature of the story essentially demands it, it is still somewhat disconcerting to skip months at a time between episodes with no explanation. So if you don't understand why it happens, it can leave you with alot of questions and confusion.
Animation/Art - 8.4/10
Pretty good animation. SAO isn't top tier by any stretch of the imagination, but it does the job well. Lots of great backgrounds and character designs, but nothing to really wow the viewer. Can sometimes fool with great vista views or epic castles but behind the facade it isn't as impressive as it appears.
Sound - 8.7/10
The sounds and music in SAO are pretty decent. OPs and EDs are solid but not top tier. General soundtrack solid and everything else does the job good enough. Again though, nothing here that is outstanding or memorable.
Characters - 8.5/10
SAO's main strength was the relationship between the main 2 characters and the strong, likeable support cast. Whilst the series doesn't break any moulds with it's character archtypes it doesn each one well. However, the side story/filler girls are all weak characters that bring nothing to the show, even as filler. Also, the "villians" in the show are also below par. The Aincrad arc villian is different from alot of other villians, but that doesn't make him a strong character. The Alfheim villian is a really bad crazy, mental sadist type who is weak even for that archtype.
Overall - 8.2/10
I still gave this a 5 stars on here, as a fan. It was still very enjoyable and the only point I would say truly detracts from the experience is the way each arcs ends. Everything else either has its reasons to be that way or is an issue so common in anime that it's something that, at least I could deal with.
As a reviewer though, the show is about average. It had the promise to be so much better than it was and recieves alot of praise and reviews as though it truly did hit those heights. At the same time, it recieved alot of hate as though it was bottom of the barrel stuff but the series is definitely better than that.