Reduced level controllers to one. Made animation
Aziz helped me realize that I didn't need a factory to pass the level number into each controller (in order to just use one controller for all levels) and that all I needed to to was pass an argument to the controller via ng-href. Also changed the UI of the level buttons some. And made green and red flashes work for right and wrong answers - which was tough because the same css animation can't play twice in a row, so I had to add and remove the animation class each time the animation is played.