Rotate a board to match same colored gems and remove them!
Colored Gems fall from the top. Press A or Arrow left to rotate counter clockwise. Press D or Arrow right to rotate clockwise. Press S or Arrow down to drop gems instantly. Click on groups of 3 or more same colored gems to remove them. When you have collected enough gems of a color, the word 'Ready' will appear next to the gem at the right, and you can pop all gems of that color.