Grab a ball of your choice (on the screen, dude!) and drag it either clockwise or couterclockwise around the triplet center. It's easier than it sounds.
It's either against the clock (timed mode) or with infinite time but limited energy (skilled mode).
Points are summed and with each level you get more energy/time for the next game.
You can disable the pattern mode (or smilies) under settings if you hate smilies.