Monos is a falling block puzzle game, similar to Tetris, but with irregular shapes of different colours and the goal to form colour matches instead of lines. Shapes include rectangles, circles and triangles of various sizes that drop down the screen. They can be rotated and slide along other objects to place them in the desired position. To create a match and remove the shapes from the field, two items of an identical colour need to touch. They do not disappear immediately, as it takes a while. When they disappear, all shapes on top of it drop down. The game only contains an Arcade mode, with three difficulty levels, where the game speed gradually increases, and it keeps track of the player's high score.