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