Here is the full list of all 45 Broken Age achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Complete Broken Age
Start a group dance party
Stand up for someone even though you haven't met her
Talk to the boss
Complete Act 2 of Broken Age
Find a genius
Commission a custom garment
Return a heavy duty spaceship part
Clear up a tangled situation in one attempt
Return a missing spaceship part
Get a family member's help on a big project
Chart a course away from danger
Deploy a weapon of mass destruction
Remove 8 sad faces from the Bassinostra
Uncover an unsavory scheme
Get to the ship's brain
Answer some tough questions quickly
Complete Act 1 of Broken Age
Take down Mog Chothra
Leave an isolated town
Reunite a mother and child
Get to know someone in a precarious position
Travel to a forbidden location
Take Control of the Boom Arms
Inhibit a powerful entitiy
Disrupt Shay's daily routine
Escape the Maidens Feast
Learn all you can about Sugar Bunting
Examine all breakfast options
Unlock all Broken Age Achievements
Make a Spoon Sweat
Complete all rescue missions with zero errors
Hear 20 reasons why Gary won't grab that
Feed two different people a healthy snack
Endure a tight situation as long as you can
Find 30 unique reactions to the Spoon
Visit someone in jail
Tell a great joke in one attempt
Follow up on a successful performance
Execute a PERFECT escape
Get to know a stranger
Reconnect with some old friends
Make someone strut their stuff
Stand up for someone even though you haven't met him
Complete Broken Age in under an hour, not counting loading and paused gameplay.