 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.
