I really wanted to make this because i felt many of the issues with comparing different stories with MMO involved, are not always fair. First off, i want to clarify the difference between an story with an MMORPG setting, and a MMO themed story.
Stories with MMO setting:
Stories using MMORPG as a setting more than as the main theme don't necessarily explain a lot as to how the MMORPG works, and how it can be successful if it was a real game. Creative license usually takes over above all else if it means telling a compelling story. The biggest example of this is dot-hack. Dot-hack has an MMORPG known simply as "The World". Its distinct and easy to tell that it's a fantasy MMO. But usually doesn't explain "how" the MMO, just enough to know how it effects the story. Most of the times the themes are how personalities are effected in an MMO and the curiosity of what the other person is like in the real world. In my opinion, dot-hack succeeds in what it wants to achieve. There are other things affecting the MMORPG "The World" that can't be tackled as if you were playing an MMO, the MMO is simply the obstacle they need to overcome.
Another series is "Is it wrong to pick up girls in a dungeon?". This one sort of counts but not fully as gods have transformed the world MMO-like rules such as armor, spells, and leveling up, and a simplified and easy to understand economy. But doesn't explain how you can learn these abilities or how to level up. only that it is difficult and take a long time, and for story purposes the main character manages to level up at a unusual way.
For this series, the purpose of using game mechanics was exactly to show how much progression a character has made and how much recognition which readers can understand immediately based on how this world works.
MMO-themed storiesMMO stories such as Log Horizon and SAO are stories that use MMO fully as the theme and main intent to fully make us believe that these MMOs could exist in the real world. Explaining how combat works, how leveling works, how players can have the biggest advantage is what drives the entertainment value. Log Horizon has the biggest advantage of this as the main characters are adults who major in the kind of thinking and fully take advantage of the MMO gameplay and use it to their advantage.
The SAO predicamentWhy SAO is bad? because it doesn't convey exactly what the story should be. should it be a heavily themed MMO or should it be a story that happens to use MMO as a setting?
The simplest terms as to why SAO fails is that it wants us to be immersed in the idea that SAO is going to be the first MMO to use VR. It wants us to believe in the numbers given despite the numbers not being big. It wants us to enjoy the world and the mechanics when the mechanics don't make too much sense.
So when you don't have a believable MMO, what you have left is to rely on the story. And what does this story give us? The story gives us characters that have potential to be something more than what they are. And although the story seems to make it like they did, they ended up being the same characters only getting what they want. Worst of all the main premise also doesn't make any sense and characters don't even try hard enough to explore the glaring issues. It could be that the novel explores more. But i dont believe an entire anime series would be willing to dumb down the story that much.
IN the end, rather than expanding the SAO with expansion and new mechanics, it goes make a completely new MMO with its own flaws (that make no sense for the story) and then does it again for a second time. It does explore some things that make me personally believe it wants us to think that it uses MMO setting to explore other themes, but it doesn't. Which makes it even harder to appreciate.
How to make a good MMO-themed story and a good story with MMO setting:#1) MMO needs to have a purpose (even if its not the main purpose of the story). Usually one of the biggest themed explored in both is the gap between the real world and the online world. Other themes could be explored as well.
#2) The MMO needs to have all the very basics of what makes it an MMO or one that you can see players playing. Elements such as such as getting the best armor, monsters to fight and level up, towns and/or cities for players to either trade or be social and be immersed.
#3) Make sure you focus on the story being just as compelling. Many problems SAO had is that it brought glaring issues to the story and did not address the problems at all. Characters were also very one-dimensional. If you have interesting compelling character and story on top of a great MMO theme or setting.
#4) Whatever you do introduce, make sure it's well thought out. If you're not a
**** MMO player, ask around and make sure it's not too obscure.