Here is the full list of all 39 Blacksad: Under the Skin achievements.
Watch all 6 alternate scenes at the end of the game.
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 Boxing sheet of the Hall of Fame album.
Complete the Hockey sheet of the Hall of Fame album.
Play good cop convincingly.
Help the Colberts live a second honeymoon and receive their gratitude.
Complete the game without dying a single time.
Complete the game dying less than 9 times.
Contribute to as many deaths as possible.
Now for real.
Find all false endings in the game.
Complete all deductions in the game.
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.
Take your fifth beating.
Interact with as many books as you can.
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.
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.
Stand up to Sam as many times as you can.
Take your second beating.
Take 400 nightstick blows. Maybe a few less.
Find your most valuable tool.
Do not take the case.
Take your first beating (spoiler: it won't be the last!).