The purpose of Hextris is having fun preventing the blocks from leaving the interior of the gray hexagon.
Press the right and left arrow keys or Tap the left and right sides of the screen to rotate the Hexagon.
Press the down arrow in the keyboard if you are using a computer to the block to fall faster.
You will earn points by making three or more blocks of the same color align side by side on the hexagon.
Time left before your combo streak disappears is indicated by the colored lines on the outer hexagon.