Sudoku 16 x 16

A 16 by 16 grid fills the screen. Sudoku 16 x 16 uses 256 cells and digits from 1 through 16, pushing past the usual 9 by 9 format into a larger number puzzle. Bold lines split the board into sixteen 4 by 4 sections. Every horizontal line must hold each digit once. The same rule applies to every vertical line, and no 4 by 4 section can repeat a digit.

How to play?

Fill empty cells with digits 1 to 16, using the rows, columns, and bold-marked sections as your guide. Work from the 4 by 4 areas with the most given digits if you want an easier way to place the next number. Remove a placed digit whenever a position doesn't fit. Save the current board and return later without losing progress. Load a different puzzle through the other condition button when you want a fresh layout. Adjust the gear setting to change difficulty. Higher or lower settings change how many digits appear on the board at the beginning.