Jedder Cheese has just submitted some Achievement Flag Info for
Bastion Achievements:
Jedder Cheese said:Multible Playthroughs Required, as you dont unlock gel canister before completing the game once.
Also missable as you both dont get notified of this secret skill being obtained and because you need a certain higher amount of kills with it, making casual use not likely to unlock it.

The Just Like That achievement in Bastion worth 31 pointsComplete the Kid's Dream with all ten Shrine Idols invoked.Shop, Requires you buy some of the shrine idols in the lost and found with in game currency
Shop, Requires you buy some of the shrine idols in the lost and found with in game currency

The Ashes in the Sky achievement in Bastion worth 33 pointsComplete the Survivor's Dream with all ten Shrine Idols invoked.Shop, Requires you buy some of the shrine idols in the lost and found with in game currency
Missable, as if you fall down during your first playthrough through that mission before making it to the end requires either you restart or play the game through and start a hardmode or score attack mode to reattempt.

The Hard Bargain achievement in Bastion worth 35 pointsEarn a total of at least 1,000,000 points in Score Attack ModeMultible Playthroughs Required, as you dont unlock score attack mode before completing the game once

The All in the Mind achievement in Bastion worth 33 pointsComplete the Stranger's Dream with five or more Shrine Idols invoked.Multible Playthroughs Required, as you dont unlock history bookse before completing the game once

The About the Author achievement in Bastion worth 34 pointsComplete the Stranger's Dream with all ten Shrine Idols invoked.Multible Playthroughs Required, as you dont unlock history bookse before completing the game once