Here is the full list of all 43 The Academy: The First Riddle achievements.
Take a picture of a pinecone on a tree
Solve all the paper puzzles
Re-watch the movie about the baron
Finish the game using no hints
Finish the game using less than 20 hints
Solve every book puzzle
Find the device
Solve all the puzzles
Find the sculpture
Take pictures of all blue birds
Take pictures of all the graffiti
Take pictures of all the butterflies
Finish the final exam
Save professor Wilson
Solve 7 library book puzzles
Find the hidden safe
Find 100 hints
Make time for a study session every day
Attend Self-defense class
Attend the Writing class
Solve 3 paper puzzles
Solve 50 puzzles
Find 30 hints
Take pictures of all the statues
Attend photography class
Finish 10 sidequests
Attend the First Aid class
Get 5 right answers in class
Get 5 wrong answers in class
Take pictures of all your colleagues
Take 3 pictures with the camera
Take a bath 3 days in a row
Solve 15 puzzles
Find 10 hints
Play 3 arcade games
Talk to every classmate
Attend the Painting class
Solve a puzzle in less than a minute
Make time for a study session
Take a bath
Flush the toilet and wash your hands afterwards!
Solve 5 puzzles
Finish the entrance exam