Here is the full list of all 12 Backstreets of the Mind achievements.
1st chapter is passed
2nd chapter is passed
You've choose the path of harmony with nature
You've choosed the path of conqueror of nature
You've reached 10 stars at fastfood cafe
Used less than 10 hints to complete the Game
Earned 10'000 score in Starship videogame
Became a Millionaire in 30 days
Hit all targets in Submarine videogame
Won all mini-games
Didn't use hints at scene
Didn't use any hints to complete the Game