Here is the full list of all 45 Pixel Puzzles Trivia achievements.
Attain Rank: All Knowing
Attain Rank: Genius
Attain Rank: Deep Thinker
Attain Rank: Socrates
Collect 50 Diamonds
Attain Rank: Sharp Minded
Collect All Time Trial Stars
Attain Rank: High IQ
Collect 25 Diamonds
Answer 5000 Questions
Attain Rank: Brainiac
Finish 50 Casual Quizzes
Finish 50 Time Trials
Attain Rank: Quick Witted
Finish 50 Detonation Quizzes
Finish 50 Deadline Quizzes
Finish 25 Deadline Quizzes
Attain Rank: Insightful
Finish 25 Detonation Quizzes
Answer 1000 Questions
Finish 25 Time Trials
Finish 25 Casual Quizzes
Finish 10 Deadline Quizzes
Finish 10 Detonation Quizzes
Finish 10 Time Trials
Answer 500 Questions
Attain Rank: Graduate
Finish 10 Casual Quizzes
Collect 100 Gold Pieces
Answer 100 Questions
Collect 50 Gold Pieces
Answer 50 Questions
Collect 5 Diamonds
Attain Rank: Novice
Collect 10 Gold Pieces
Answer 10 Questions
Use 1 Hint Token
Collect 500 Gold Pieces
Collect 100 Diamonds
Collect 250 Diamonds
Collect All Casual Stars
Collect All Stars
Collect 1000 Gold Pieces
Collect All Deadline Stars
Collect All Detonation Stars