Here is the full list of all 22 Bastion achievements worth 1,000 gamerscore. It takes around 15-20 hours to unlock all of the achievements on Xbox One.
Complete the story.
Complete the story in New Game Plus.
Complete the Kid's Dream with five or more Shrine Idols invoked.
Complete the Kid's Dream with all ten Shrine Idols invoked.
Complete the story, embracing the New World.
Use the Forge to apply at least one upgrade to every weapon.
Complete at least 50 percent of the Vigils in the Memorial.
Stop to the siege on the Bastion.
Get four different domesticated creatures in the Bastion.
Complete Prosper Bluff and speak with the Singer in the Bastion.
Complete the Hanging Gardens and speak with the Survivor in the Bastion.
Complete the Wharf District.
Complete each trip to Who Knows Where.
Complete 100 percent of the Vigils in the Memorial.
Use the Forge to fully upgrade every weapon.
Complete the Singer's Dream with five or more Shrine Idols invoked.
Complete the Singer's Dream with all ten Shrine Idols invoked.
Complete the Survivor's Dream with five or more Shrine Idols invoked.
Complete the Survivor's Dream with all ten Shrine Idols invoked.
Complete the Stranger's Dream with five or more Shrine Idols invoked.
Complete the Stranger's Dream with all ten Shrine Idols invoked.
Earn a total of 1,000,000 points In Score Attack Mode.