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