It is up to you to try and group spheres together to form one big blob, all of the same color. Try to group as much spheres as you can before time runs out.
The spheres automatically stick together, so grouping them shouldn’t pose any difficulties. The difficulty comes when your group starts to get big and heavy, just try to drag it around then, with the timer breathing down your neck.
Group enough spheres before time runs out.
Left click and drag a sphere around, if it touches a sphere of the same color, they will stick together. Group spheres together that have the color of the counter sphere in the centre of the screen.
If two groups touch, the color of the group with most members will be adopted by the other group.
If you want to transform a sphere to the needed color, drag it onto the counter in the center of the screen.
