Ants

Ants - scourge of picnics, carriers of stuff into anthills, destroyers of cities when they get zapped by gamma rays and grow massive in bad 1950s sci-fi films. But these ants won't be attacking people with their space-pincers. They are very obedient and will follow any wobbly line you choose to draw.

The game's creator, Joe, claims he was inspired by his niece who was given a toy for Christmas which was a small car that followed any line that you drew on a piece of paper. In the game your ants are milling around. You have to draw a line for them to follow and help them back to their home. Sounds easy, but later levels feature various obstacles and other tricky elements.