Life Force (ライフフォース Raifu Fōsu?) in North America and in the Japanese arcade re-release, is a scrolling shooter arcade game by Konami. Released in 1986 as a spin-off to Gradius, Salamander introduced a simplified power-up system, two-player cooperative gameplay and both horizontally and vertically scrolling stages. Some of these later became the norm for future Gradius games. Salamander was followed with an official sequel in 1996 entitled Salamander 2.