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