Known by its original Japanese name Salamander, the game first hit Arcades in 1986. Though Salamander did not take place entirely within an alien organism, this idea was expanded upon for its US release and given a more biological name to suit the change - Life Force.
This new organic version was re-released in Japanese Arcades with the changed name, as well as adopting Gradius' old power-up system and some additional sprite work.
Salamander's first home port would be the MSX version in 1987, which received a new story and an entirely new animated introduction sequence. The game would later see a NES version, also with reworked stages (including a skeletal vertical-scrolling stage and an Egyptian-themed stage) and the old Gradius power-up system as well as versions for many other popular home computers and consoles of the period.
In 2008 (Japan)/2009 (US) the NES version would be re-released for the Wii's Virtual Console.
Salamander is a spiritual sequel to Gradius, Konami's earlier shooter, and shares many deliberate similarities with its predecessor. The player flies the customizable spaceship Vic Viper through a series of horizontally scrolling levels, destroying enemies and collecting power-ups to assist them. Unlike Gradius, which had the player stack up tokens to unlock power-ups of their choosing, the ones found in Salamander are random. However the old Gradius system would reappear in many versions of Salamander, including the NES home version.
There exists the possibility of a second player. Instead of the blue Vic Viper, the second player pilots the red Lord British, based on the Vic Viper design.
It was noted at the time for its simulated speech samples and graphical quality, especially with some of the stage animations. Particularly memorable is one stage set in the midst of a raging inferno that would occasionally send arcs of flame flying across the screen.
Attentive players can find one of three types of power-up item while playing: These include the red power-ups, found after destroying an enemy wave or a gold-tinted enemy, which the player can spend towards power-ups provided they have the right amount. The player can also run across blue power-ups, which work as instantaneous smart bombs that clear the screen of enemies, and the rare flashing power-ups that grant an extra ship.
- Speed Up: The cheapest power-up, Speed Up makes the ship faster, allowing for more maneuverability.
- Missile: This power-up allows the player's ship (and any Options they might have) to launch two missiles from the top/bottom of the ship (or left/right in vertical stages) which coast along walls until they either hit something or leave the screen. The player can select the missile power-up again to increase their speed.
- Ripple: A weapon that fires rings of energy at enemies. The rings expand the further they get away from the ship, making them useful for hitting multiple targets accurately.
- Laser: A concentrated laser beam of considerable power. Selecting Laser again makes it wider and slower. The beam will actually travel with the ship's movements, allowing the player to sweep the screen with it. Can't be used simultaneously with the Ripple beam: Activating one deactivates the other.
- Option: An Option is an additional weapon platform that follows the main ship. It is able to fire all the weapons the main ship can, essentially doubling the player's firepower. In the US version, up to two Options can be obtained, though this number increases to three for the Japanese version. A side-effect is that enemy units become stronger to compensate for this added power.