Here is the full list of all 16 Sir Questionnaire achievements.
Reach floor 5
Reach floor 10
Reach floor 15
Complete an easy quest
Collect your first crown
Commit Dungeon Genocide
Kill a minotaur
Kill an orc
Kill a Mud monster
Complete a hard Quest
Metamorphosis
Force a spitting heart
Turn something to stone
Beat the boss
Complete a medium Quest
Visit the boss lair