I think the best way to describe Bastion was something my girlfriend said. I booted up the game, started my first playthrough, and from across the room it was simply:
"What is that? It looks amazing!"
She doesn't even play computer games. At most you could find her deeply involved in a round of Words With Friends, but that would be about the extent of her "gaming." So for a game to gain her interest to that degree is something worth a great deal of praise. The art direction is just that good. Vibrant colors, and crisply drawn environments are painterly. The use of colors perfectly conveys the appropriate feeling for the story at that moment, and all of the areas have their own unique flavors. You want to keep exploring it to find out what's just around the bend. Put together with simple controls and yet an extremely complex combat system makes for a unique taste of action RPG adventure.
The way the game world builds itself up around you as you walk through it is not only a plot device, but an exceptionally amazing way to grab your attention from the first moment you step into Bastion. Combined with the subtle narrator voice dictating your story to you as you perform it makes this more than just an RPG. It grabs you and says, "Hey you. Take notice. Bastion is something you'll want to discover." The story involves you in a way that few games can achieve because of all the little details. The narration makes the story more personal, there's no gigantic walls of text to read and since everything is being told to you during your adventure you gain a connection between the narrator and your actions.
He's telling you what you need to know, and he's telling you about yourself. It's all canned recordings, but the manner in which this information is presented to you makes it feel natural, fluid almost. It feels like your personal story, not some list pre-recorded plot highlights.
Bastion is the game you want to keep playing and it's the little details that make it succeed so well.