How it works:
Click a board to begin, timing starts right away, so be ready!

Difficulty:
Difficulty is determined by your usage of hints.
If you never request a hint, the board difficulty remains hard.
If you request a medium hint, the board gets set to medium, if applicable, and the board moves the focus to a solvable square.
If you request an easy hint, the board gets set to easy, if applicable, and a solvable square is filled in.