Life Force was in many ways an updated Salamander; some elements, such as levels and bosses, were removed to make space for new content. Interestingly, most of the level graphics and enemy sprites from Salamander were used in favor of the ones used in Life Force, and it uses the Gradius power-up bar. The game was practically identical to the NES port of Life Force, other than being titled Salamander and featuring an expanded Gradius-like power-up bar. These ports make use of the Konami code, which in this instance increases the number of lives from 3 to 30.
Life Force changes the plot from Salamander by adding an opening text which establishes the game to be set inside a giant alien life-form infected by a strain of bacteria. Stages which featured star field backgrounds had them changed with the web background from Stage 1 to maintain consistency with the organic setting of the plot. The power-ups are also given different names too:
- "Speed-Up" to "Hyper Speed"
- "Missile" to "Destruct Missile"
- "Ripple Laser" to "Pulse Laser"
- "Force Field" to "Shield"
Konami later released an enhanced version of Salamander in Japan bearing the American title of Life Force, which further fleshes out the organic motif. All of the backgrounds and mechanical enemies are completely redrawn and given organic appearances. The power-up system was also modified, with the Japanese Life Force using the same power-up gauge as the original Gradius. Some music tracks have also been completely changed for this release. The power-up gauge is arranged differently for both players as well.
Both the original Japanese version and the enhanced Life Force release are included in the compilation Salamander Deluxe Pack for the PlayStation and Saturn, as well as in Salamander Portable for the PlayStation Portable.
- Interestingly, Life Force takes place in Gradius year 6842, two years after Gradius III.
- The Garden of Time in 2004 anime Magical Girl Lyrical Nanoha somewhat resembles the Life Force (Fortress)
|Ships||Vic Viper • Lord British • Sabel Tiger (Iggy Rock) • Thrasher (Zowie Scott) • Super Cobra|
|Salamander stages||Bionic Germ • Meteorite Space • Ratis • Volcano Area • Salamander Planetoid|
|Salamander (MSX) stages||Top Flight Speed to Latis • Conduct to Space Station Zot • Set the Crush Blow System - Planet Eioneus • Set the Crush Blow System - Planet Lavinia • Set the Crush Blow System - Planet Kierke • Wrath of Venom • Crush Salamander|
|Life Force-only stages||Organic Speed Zone • Temple Zone|
|Salamander 2 stages||Organic Sky • Artificial Suns • Resident Evil • Battleship Armada • Ruins of Final Base • Crystal Asteroids • Doom Fortress|
|Salamander bosses||Brain Golem • Tetran • Intruder • Center Core • Death • Big Core X3 • Jumping Moai • Zelos Force|
|Port exclusive bosses||Zylom • Gau • Invader • Giga • Tutanhamanattack • Dead End • Enigma • True Venom • Metal Slave • Zelos Barrier|
|Salamander 2 bosses||Biter • Hydra • Abadon • Tenny Rop • Plate Core • Cerberus • Doom|
|Gradius Video Games|
|Gradius series||Gradius • Gradius II • Gradius III • Gradius Gaiden • Gradius IV • Gradius Galaxies • Gradius V • Gradius ReBirth • Gradius: The Interstellar Assault • Gradius NEO • Gradius NEO Imperial • Gradius Arc|
|Spin-offs||Salamander (Life Force) (MSX ver.)• Salamander 2 • Nemesis (MSX) • Nemesis 2 (Nemesis '90 Kai) • Nemesis 3 • Nemesis (Game Boy) • Cosmic Wars • Solar Assault|
|Parody games||Parodius • Parodius Da! • Gokujō Parodius! • Jikkyō Oshaberi Parodius • Sexy Parodius • Paro Wars • Otomedius (Otomedius Gorgeous) • Otomedius X: Excellent!|
|TwinBee||TwinBee • Stinger • TwinBee 3: Poko Poko Daimaō • TwinBee Da!! • Detana!! TwinBee • Pop n' Twinbee • TwinBee: Rainbow Bell Adventure • TwinBee Yahoo! • TwinBee Taisen Puzzle Dama • TwinBee RPG • TwinBee Dungeon • Pastel Jan|
|Other games||Scramble • Flak Attack • A-JAX • Falsion • Thunder Cross • Thunder Cross II • Space Manbow • Quarth • Trigon • Crisis Force • Xexex|