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