In Crackpots, you play as Potsy a gardener. Potsy's Brooklyn building is being overrun by bugs trying to climb inside six different windows. You move Potsy back and forth along the roof to drop pots on the bugs before they get too close to enter the windows.
The types of insects enter the walls in different patterns. Black bugs will move straight up the building, blue bugs wiggle from left to right, red bugs move diagonally, and green bugs zig-zag between windows. Each level consists of four waves of twelve bugs each; defeat all four waves and you'll move on to a faster-paced level. Play then resumes until your building crumbles to the ground. Whenever you allow six bugs to enter the windows, one of the building's six layers will disappear and you'll begin the next wave closer to the ground.
Source: Wikipedia, Crackpots , available under the CC-BY-SA License.