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