Each game field side has bricks available. After tap brick starts moving through the field until it hits another one (you can't choose a brick that has no obstacles on the way). Arrow on each brick shows move direction if there are no obstacles on the way. Group of 3 or more bricks of same color that share a common side vertically or horizontally will be removed. Then other bricks with arrow will automatically move till they hit obstacle. When no bricks left on the field level is cleared.