I've played through Bastion once. I am playing through it again on the New Game + mode. Bastion is the rare type of game that comes in, makes a remarkable impression, and then leaves before its stuck around too long. It also has my juices flowing for a bunch of thoughts about things I'd like to see in an MMO.
The first and most unique element of Bastion is the narrator which narrates not only the story, but the player's every move. When I first talked about Bastion's narration to my wife she commented "so he just repeats back to you what you just did? That's annoying!". I attempted to sidetrack her from that position by showing her some of the game, but then "the kid" (the game's protagonist) picked up a giant hammer to which the narrator announced "the kid picks up his trusty hammer". My wife laughed and walked away. While this example is the game's narration at it's most basic it is not truly the genius that exists later in the game. The narrator is seemless, delivering not only the story but also filling in the gaps between fights and everything else that occurs in the game. By the time I finished Bastion I was a bit sad to say good bye to the narrator. I had grown accustomed to listening to his voice through my journey. It probably doesn't hurt that they have one of the best voice actors ever providing the voice and paired it with an award-winning sound track.
Where would a constant narrator fit into an MMOG? The first immediate example that comes to mind is Dungeons and Dragons Online (DDO). I know I gave DDO a bunch of hate because it was just an RPG set in the D&D Eberron setting and because it missed the boat as far as what makes D&D fun (at least for me). With my personal tastes aside, DDO to a certain degree does have a narrator in place, known as the dungeon master. When adventuring through various dungeon areas the dungeon master will announce certain things such as the "the air hums with flies here" or "the smell of decaying flesh permeates". Usually these pieces of flavor are added for things that are hard to represent in a video game (smells for example). I wasn't sold on the idea when I played DDO, but having played Bastion now I think a dungeon master that follows your entire adventure and provides constantly evolving narration to your activities would work. The real trick would be making it work in a multi-player setting, which given some time I think a developer could work out.
The next outstanding feature of Bastion is it's namesake. The Bastion is a sliver of land, floating over the destroyed world that "the kid" is able to rebuild throughout the process of the game. Each area completed generally results in a shard being obtained. The shard can be brought back to the Bastion to restore a piece of the old world. These restored parts take the form of buildings that allow the player to perform different functions. In addition to the shards there are also relics from the old world that can be placed in the Bastion. Everything from a set of banners to a smoker's pipe add flavor to the player's Bastion. Some are for show and others serve other purposes (such as launching a side quest). Over time there is a real sense of progression to the Bastion.
Now it has always been my dream to have an MMO where the players are tasked with building the world from the ground up. The storyline in Bastion is the classic post-apocalyptic hotbed of building an oasis in the middle of a world wracked by destruction. This, to me, is the perfect setting for an MMO to launch into. It lets the players decide the pace at which the world progresses. Players hold the keys and make the decisions that will forever change their existence in the world. The so called "fourth pillar" of MMOGs is touted to be "story", but why does that story always have to be something the developers created? Why can't it be the story the player's create?
For bonus points, Bastion gets the mechanic for this world building correct as well. Players retrieve shards or relics that have immediate affects on their Bastion. In the case of shards, the player get's to spend them as a sort of currency to build the buildings they wish to have in the Bastion. This is almost directly transferable to an MMOG. Player's would be tasked with retrieving "shards" from the old, destroyed world to use and build items in the new world. Each player would have their slice of the new world in which to build. Guilds and alliances can join together to focus on improving a shared area.
Another part of the Bastion experience that makes the game so refreshing is the idea of player-directed difficulty via the in-game idols. Players can go to their shrine and activate idols they have unlocked. Each idol makes the game inherently more difficult. For example, one idol makes it so enemies randomly block one attack. The reward is increased experience gains and in-game currency. It's a simple idea, but something not seen in an MMO outside of the idea of "heroic" versions of some dungeons. Now it would be a challenge to develop, but I think an MMO could have every player set their own idols to dictate their own difficulty. The challenge would be in making it play nice together with other player's idols.
The other part of the shrine that works so well is that it's not just a UI element in Bastion. It is an actual building the player has fought to restore for the sole purpose of using it's services. This gives better weight to the player setting their idols and takes something that in most MMOs is just a UI element and makes it part of the world. Everything in Bastion is managed via these buildings that the player builds. Want to change your equipment load out? Head to the armory and swap them. Want to change your unique character traits? Head to the distillery.
Oh and the distillery. Let me talk about that. It's a brilliant idea just like the shrine is. In the distillery player's set up "spirits" (aka alcoholic beverages) which modify how the player's avatar works. Some add straight up stats like +10 health while others are more complex such as offering a counter attack mechanic. However, the beauty really isn't in the details. It's in the fact that the distillery takes the monotony of the stats screen out of the UI and inserts it into a practical in-game solution. It doesn't hurt that the player can visit the distillery at any time to "respec" their character.
I understand some of the ideas I bring up here are not entirely original and in most cases there is an example game on the market that exhibits some of the traits that I mention. However, there really hasn't been a mainstream game that has attempted to tackle any of these elements. "The game that shall not be named" with full on voice acting does cover some of the narration, but it is not dynamic and at it's base level is still just uninteresting filler for quests. Bastion's narration is so far above and beyond that it's hard to compare. A Tale in the Desert covers the "let's build a world together", but really that's about all it has. Plenty of MMOGs feature "hard" or "elite" versions of dungeons, quests, or monsters which sort of works out to be like the idols of Bastion, but that's a loose connection at best. The "UI-built-into-the-game" element would be a first for MMOGs, as far as I know. In fact, a lot of MMOGs are more about the UI then the actual game (I'm looking at you EVE and at you World of Add Ons), so seeing an MMOG work towards removing as much of the UI as possible would be interesting.
My concluding point is that we haven't seen an MMO that incorporates a lot of what I've talked about and that's a damn shame. Bastion feels like a really simple idea, but its clearly taken time for something of it's caliber to hit the market. It's a brilliant game and in my opinion, a blue print for a successful MMOG.