How to play
Fill the 4ร4 board so that each row, column, and 2ร2 box contains 1โ4 without repeats. Each puzzle has exactly one solution. The supplied clues cannot be changed.
Select a cell, then use the number buttons or keys 1โ4. The erase button, Backspace, and Delete clear your own entries. Repeated digits are marked; arrow keys move the selection.
P or Escape pauses and resumes while the board has focus. Clicking outside the game or switching windows pauses automatically.