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