Earth Defense Force (also called Super Earth Defense Force E.D.F. in-game and Super E.D.F. in Japan) is a horizontal shooter game developed and published by Jaleco for the SNES. Originally an arcade game, it featured a two player cooperative gaming mode which was later removed during its port to the SNES. In its SNES incarnation, graphical adjustments were made to some of the game's levels, and new selectable weapons were added. It is also scheduled for a future release on the Wii Virtual Console.
The story varies between the different versions of the game.
The Arcade original takes place in the equivocate future date of Earth, 20XX. An armada representing the alien Azyma Empire threatens to destroy Earth with the Orbital Buster, a large, computerized space satellite as the armada's flagship. The Earth's only hope lies in the recently developed XA-1 spaceships held under the organization known as E.D.F: Earth Defense Force.
In the Super Nintendo version, the malevolent aliens of the Azyma Empire has populated the dark side of The Moon. After initiating an attack on the Earth, it is revealed they have a secret weapon being developed on The Moon, one capable of destroying all life on Earth. The E.D.F. is ordered to send their XA-1 fighters in to drive out the invaders and destroy their ultimate weapon.
Released as a horizontal shooter game in the US in January 1992, the object of Earth Defense Force is based on survival of the game's levels, punctuated by the defeat of bosses at the end of each one. It is a fixed-length game, with a proper ending at the completion of the last level.
The player normally begins each level with 3 "shield" points, each able to absorb one enemy attack. The shield points are represented in the upper right corner by green ovals under the heading "Shield". Additional shield points can be earned once a predetermined game score is reached. Up to five shield points are represented on screen. However, a player can acquire more than five shield points, but they can not be seen. This is extremely rare though, due to the difficulty of the game and the score intervals at which additional shield point. Loss of all shields results in the loss of one of 3 credits, or continues, and loss of all continues results in the player seeing the game over screen.
Reception and legacy
Since its release, Earth Defense Force has met with moderate critical reviews, as evidenced by a three out of five star rating by Allgame. Subsequent to its release an enhanced version was broadcast via the SNES' Satellaview subsystem to Japanese gamers under the title BS Super Earth Defense Force.