Inchworms have an important part in the game. In the level Pyramid of the Moons, you can collect 12 inchworms by moving slowly enough for them to follow you. Once all the 12 are on your feet, ’12 inches makes a foot’, they will transform into a giant Foot. (Source: KeenWiki)

I literally did not realize the “12 inches make a foot” thing until this very moment when I grabbed the reference above. But whatever. One pun is as good as the next I suppose.