Here is the full list of all 35 The Detractor achievements.
Defeat your first opponent.
Defeat 10 opponents.
Defeat 25 opponents.
Complete chapter I.
Complete chapter II.
Complete chapter III.
Win an arm wrestling match.
Win an arm wrestling match 5 times.
Reach a score of 6 at the piano.
Reach a score of 8 at the piano.
Reach a score of 10 at the piano.
Complete the puzzle game under 20 seconds.
Score 10 points at Flappy Pig.
Score 20 points at Flappy Pig.
Score 40 points at Flappy Pig.
Reach a combo score of 10.
Reach a combo score of 20.
Reach a combo score of 30.
Complete the game.
Complete the game without casting any spell.
Defeat 50 opponents.
Defeat 75 opponents.
Defeat 100 opponents.
Defeat 150 opponents.
Win an arm wrestling match 10 times.
Reach a punch score of 70.
Reach a punch score of 80.
Reach a punch score of 90.
Complete the memory puzzle under 25 seconds.
Complete the memory puzzle under 18 seconds.
Complete the memory puzzle under 11 seconds.
Complete the puzzle game under 15 seconds.
Complete the puzzle game under 10 seconds.
Complete the game without taking a hit.
Complete the game without using items.