For some it's staying low on the play field, steadily advancing through the levels, for others its trying to clear the board entirely or scoring an unprecedented number of tetrises.

Indeed, some of the little naked human figures seemed to display a near comical sangfroid, even as they were pecked by giant birds, hatched out of eggs, had huge flowers inserted in their bottoms, or, in the case of one of my favourites, sported a monstrous blueberry instead of a head.

The children were immediately entranced by all the balloons.

Palaeoichnology would indeed be refined if the originator of each series of trails could be determined as to species, following which normal biosystematic nomenclature would be available.