Here is the full list of all 35 Sudoku Quest achievements.
Fully reveal 500 boards.
Fully reveal 100 Classic Sudokus.
Fully reveal 250 boards.
Fully reveal 100 Overlapped Classics Sudokus.
Reveal 10000 cells.
Fully reveal 100 Nonomino Sudokus.
Complete 25th adventure level.
Fully reveal 100 boards.
Reveal 5000 cells.
Fully reveal 50 boards.
Collect 10000 gold in total.
Complete 20th adventure level.
Use "Show possible values" power-up 20 times while playing any adventure level.
Collect 5000 gold in total.
Fully reveal Overlapped Classics Sudoku in under N minutes, where N is the number of grids.
Fully reveal Nonomino Sudoku In under 1 minute.
After activating "Shuffle" power-up fully reveal board in under 30 seconds with at least 5 unrevealed cells.
Fully reveal Classic Sudoku with 30 or less givens.
Fully reveal Classic Sudoku with 20 or less givens.
Finish Classic Sudoku by placing the last number in the exact center of the grid.
Fully reveal Classic Sudoku in under 1 minute.
Reveal first 7 cells in under 10 seconds, starting from first reveal while playing any adventure level.
Have 2500 gold at once.
Reveal 1000 cells.
Complete 15th adventure level.
Fully reveal Classic Sudoku with 40 or less givens.
Complete 10th adventure level.
Complete 10 adventure levels in a row without using power-ups.
Have 1000 gold at once.
Complete 5 adventure levels in a row without using power-ups.
Complete 5th adventure level.
Complete 1st adventure level.
Complete 1 adventure level without using power-ups.
Complete any adventure level without mistakes.
Complete any adventure level without using pencil.