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