Picross is a picture crossword puzzle where you follow the clues to reveal a hidden picture. The board size ranges from a 5x5 block grid up to a 20x15 block grid, and all board sizes can range from easy to challenging.
To play, you use the numbers to fill in the blocks on the grid. Each number represents how many blocks are in a group. For example, 22 would be 2 sets of 2 blocks. In a 5x5 board, the middle block would be left untouched while the 2 blocks on the left and right would be filled in.