First you look at the screen to see what the scientist is saying. The black mouse pointer goes (almost) where your mouse pointer goes. When you see the bar, add enough Code It sweet hearts to make the egg not spicy (put the mouse in the green section, in other words). If you touch the red section, you will lose and not be able to play again (unless you reload it). If you touch the yellow section, you will get a second chance.
ENJOYYY!!!! [based on Wilbur Scoville's 151st Birthday Google Doodle]