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.