In 1979, Namco's "Galaxian"—"the granddaddy of all top-down shooters", according to IGN—was released. Its use of colour graphics and individualised antagonists were considered "strong evolutionary concepts" among space ship games. That same year saw the release of SNK's debut shoot 'em up "Ozma Wars", notable for being the first action game to feature a supply of energy, resembling a life bar, a mechanic that has now become common in the majority of modern action games. It also featured vertically scrolling backgrounds and enemies.