In this game you need to remove as many groups of blocks as you can before they stack up and reach the danger zone.
To remove the blocks, you tap on groups of 3 or more blocks of the same color. The groups can be stacked vertically, lined up horizontally, or a combination of both.
Pay attention to the new line of blocks that is forming at the bottom and will move the blocks up when it is ready.
If you dont want to wait until the new line becomes ready, you can swipe up the screen to add it to the blocks right the way.