marbles (n.)
children's game, from plural of marble (n.); first recorded by that name in 1709 but probably older (it was known in 13c. German as tribekugeln) and originally played with small balls of polished marble or alabaster, later clay; the modern glass ones with the colored swirl date from 1840s.

Meaning "mental faculties, common sense" is from 1927, American English slang, perhaps [OED] from earlier slang marbles "furniture, personal effects, 'the goods' " (1864, Hotten), a corrupt translation of French meubles (plural) "furniture" (see furniture).