Here is the full list of all 27 The Gallery - there are Episode 2: Heart of the Emberstone achievements.
Collect, view, and read all the lore in the game.
View all the Polaroids in the game.
Kill the captured Wizgog.
Activate the Easter Egg.
Pop a Wizgog without using the Arbalest.
Reunite the spectators of the Cull.
Build a small tower in the Culling Grounds.
Give Hermie a new home.
Finish the game without harming any Wizgogs.
Have a nap in the Transport Room tent.
Blast 10 corpses with a single Arbalest shot.
Read all the stories of the people of Ember.
Solve every Gauntlet puzzle.
Complete Episode 2.
Kill the Mother Wizgog.
Send a corpse down the shaft in the Tower of Cogs.
Repair the Solar Engine.
Clear the crypt without using the flashlight.
Collect all the tapes in the game.
Complete every cog puzzle and unlock Sebastian's safe.
Obtain the Grasp.
Meet the Beast.
Complete the game within a 93 minute runtime.
Kill every Wizgog in the Culling Grounds.
Play the Cosmic Key.
Dismember 44 limbs.
Build a large tower in the Culling Grounds.