Sudoku Hero

You control the cursor, clicking on empty squares in the nine-by-nine grid to input digits. The objective is to complete the puzzle so that every row, every column, and every three-by-three subgrid contains the numbers one through nine, with no repeats. You can play against a timer for pressure, or take your time in an untimed mode. If you hit a wall, there was usually a hint or solver function to nudge you forward. The difficulty ramps up across several levels, starting with plenty of given numbers and gradually presenting sparser, more challenging boards. It feels like a clean, focused test of pattern recognition and patience.