Here is the full list of all 39 Blacksad: Under the Skin achievements.
Find all false endings in the game.
Buy your favorite goat a second burger.
Take 400 nightstick blows. Maybe a few less.
Interact with as many books as you can.
Get hired twice for the same case.
Complete the game without dying a single time.
Complete the game dying less than 9 times.
Now for real.
Solve the case.
Take your sixth beating.
Do not scare Brunhilda while telling her a story.
Beat someone up for once.
Play baseball.
Complete Blacksad's silence conveniently.
Play bad cop convincingly.
Play good cop convincingly.
Take your fifth beating.
Why's that poster in Dunn's flat?
Put your acting skills to the test.
Stand up to Quince as many times as you can.
Help the Colberts live a second honeymoon and receive their gratitude.
Charm Helen Moore into giving you a present.
Take your fourth beating.
Buy a box of cigarettes from the nursing staff.
Take your third beating.
Take a ride with the city's most honest bookmarker.
Take your second beating.
Find your most valuable tool.
Do not take the case.
Take your first beating (spoiler: it won't be the last!).
Complete all deductions in the game.
Complete the Hockey sheet of the Hall of Fame album.
Complete the Football sheet of the Hall of Fame album.
Complete the Boxing sheet of the Hall of Fame album.
Complete the Baseball sheet of the Hall of Fame album.
Complete the Hall of Fame album.
Watch all 6 alternate scenes at the end of the game.
Contribute to as many deaths as possible.
Stand up to Sam as many times as you can.