Hard Sudoku

This app is built for Sudoku players who crave a real challenge. Every puzzle is hard—no warm-ups, no filler, no fluff. You’re allowed up to five mistakes per puzzle; make a sixth, and the grid resets. It’s unforgiving, but fair. Puzzles are grouped into themed packs, each one designed to test your logic, focus, and endurance. To unlock the next pack, you’ll need to complete every grid in the current one—no skipping ahead. There are no hints, no shortcuts, and no mercy. Just pure deduction, steady progress, and the deep satisfaction of solving something genuinely tough.