Here is the full list of all 12 Bloody Good Time achievements.
During an Infected scene, pass on your infection in the final 5 seconds and end the round clean
Finish a match as each character
Earn 200 Stars in your career
Win a match on each level
Commit your first murder
Escape from Security with a 10 Star fine
During a Hunt the Leader scene, survive the whole round as the Leader without being killed
Commit a perfect murder (boast, 5 star kill, humiliate)
During a Hunt or Elimination scene, kill your Hunter 3 times in a single round
Earn 2000 Stars in your career
Win a match without being killed
During a Scene Stealer scene, hold onto the statue for 60 seconds without being killed