In philosophy, substance means, approximately, that element of an object without which it would not exist. In the millennia-old Aristotelian tradition[?], as well as early modern[?] traditions that follow it, substances are treated as having attributes[?] and modes[?].
... and rewarding, and once the player has gotten through a level there are bonuses to collect, record times to beat, and a gold star for getting through the level without ...