Life Force Nintendo

Life Force (also known in Japan and Europe as Salamander) is a sci-fi shoot-'em-up developed and released by Konami in 1986.

A spin-off of the 1985 game Gradius, Life Force puts players back in control of the starfighter Vic Viper (known in the NA version as U.S.S. Light Speed) as they either repel an invasion of the planet Latis from the Bacterion cluster's Salamander Army (in the later JP and EU versions), destroy a brain tumor in an infected massive half-human half-biomechanical warrior named Sentinel XR1 (in the NA version), or destroy mysterious super-organism "Life Force" (in the later JP version).

While similar in gameplay to the original Gradius, Life Force is different due to its lack of a checkpoint system (with players respawning in the same area), two-player synchronous multiplayer, both side-scrolling and vertical-scrolling stages, and a new power-up system (where enemies drop power-ups directly). Certain versions of the game, notably in the later Japanese version, reverts back to the standard Power Meter system of the original Gradius.

The Salamander version and both Life Force versions have numerous differences due to their altered story. Taking place inside a giant organism, both Life Force versions replaces the backgrounds of certain stages (from vast starfields to more organic environments) and add additional voice samples and text.

The Salamander version of the game received multiple ports, re-releases, and a dedicated sequel. All versions were included in multiple compilations.