Picross is a logic-based puzzle game that involves filling in squares on a grid to reveal a hidden picture. Each row and column has a set of numbers that indicate how many consecutive squares should be filled in. Players use these clues to deduce which squares to color in and which to leave blank. The game typically features grids of various sizes, ranging from small 5x5 to larger 20x20 or more. As players progress, the puzzles can become more complex, requiring careful reasoning and strategy to solve. Picross is popular on various platforms, including mobile devices and gaming consoles.