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