Superfluous Symbol

Colored shapes above, colored shape buttons below. Find the button with the extra shape not shown above to score a point. It's simple, but can you do it in a few seconds? 

Pressing the correct button adds 2 seconds, but pressing the wrong button subtracts 2 seconds. How long will you last?

Made for touchscreens, but works with mouse. iPhone might not work :(

"Art" and Programming by William Koyama (me)
Music and Sound by Carlo del Mundo