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