The idea is to prevent the falling balls from filling up a container. Using keys 1..4 , you switch colors. You can clear only balls that match the selected color. Every time you clear a ball , you gain experience and you level up your quad power. With higher quad power, you clear more balls with one click. So if your quad power is level 2 , you clear 2 balls with the selected color. Pressing spacebar, will clear all the balls , but will leave you with half of your current multiplier. If you click on a ball with different color than the selected one , your multiplier decreases by 1 , if hit it right you increase it.
