Here is the full list of all 31 Chicken Police achievements.
Get all personal informations
Get the secret ending!
Disturb Bloodbolye's peace at least three times
Finish the game with 0 failed questionings
Complete all the questionings with "Living Legend" results
Kill the 2 lights of the enemy car in one of the car chase sequences
Find all 10 Chicken Police novels
Get all the collectible extras
Die at least 3 times on the burning ship
Ask Natasha about Ibn Wessler in her room
Get all the 58 art gallery pictures
Reach the ending
Get all the cutscenes of the game
Complete chapter four
Get to the point where Natasha kills Albert Wessler
Talk with all the characters in the game
Get all codex entries
Talk to Marty about the case that separated the Chicken Police
Visit all the limited locations
Talk to Marty about his feelings before confronting Wessler
Talk with the "super-fan" nurse at the asylum
Complete the third chapter
Collect all the songs for the jukebox
Help Mort get a room for the night
Complete the second chapter
Complete the first chapter
Get a "Frank Drebin" grade on a questioning
Steal that fancy whisky from the Czar Club
Score at least 5000 points at the shooting range
Visit the Hop-Dog after the first Police scene
Get a "Living Legend" grade on a questioning