Life Force is a scrolling shooter released on the NES by Konami in 1987. The game features standard genre gameplay, but with a unique theme; you fight giant brains with arms, avoid pointy space-teeth, and dodge fiery indigestion. The ships the player controls are essentially antibodies destroying infections (as well as seemingly normal Space Organs) inside of the giant, planet-eating Space Snake seen on the game's box. Another unique element is that the game alternates viewpoint between each stage, switching between side-scrolling and overhead views. Along the way, you collect items that fill a power-up meter which can be activated when you please, giving you increased speed, missiles, a ring-shaped beam, a laser beam, a force field, or everyone's favorite, Options; little sub-ships that follow you around and double your armament. This game is a Gradius spinoff, and it shows, down to sharing some of the same enemies, but of the two, Life Force is the stronger game.
