Here is the full list of all 15 Super Turbo Sudoku achievements.
Complete Level 31-60
Complete Level 61-90
Unlock 45 Stars in Level 61-90
Finish an easy Sudoku with 3 Stars
Finish a medium Sudoku with 3 Stars
Finish a hard Sudoku with 3 Stars
Finish a very hard Sudoku with 3 Stars
Finish an insane Sudoku with 3 Stars
Complete Level 1-30
Unlock 45 Stars in Level 1-30
Unlock 45 Stars in Level 31-60
Use the Sudoku Solver
Make your own Sudoku
Solve your own Sudoku
Finish a very easy Sudoku with 3 Stars