Here is the full list of all 15 Grand Pigeon's Duty achievements.
Pass really difficult level without mistakes.
Don't leave the game in the initial speech Cipher and join the resistance.
Make a mistake in the preparation of serum.
Choose Klaus.
Choose Irwin.
Choose Cipher.
Let Irwin destroy the city.
Defeat Irwin.
Complete line of Cipher and his resistance.
Revenge for the death of Klaus.
Complete line of Klaus with positive consequences.
Save the Preacher's life.
Complete line of Irwin with negative consequences.
Complete line of Irwin with positive consequences.
Complete line of Klaus with negative consequences.