The player must use the two-way joystick to direct a yellow ship left and right across the bottom of the screen, using single button to fire shots at the various types of enemies. The first stage consists of fighting a formation of Super Mosquitoes, which are worth 20 points each. The second stage, which has a dotted orange line under the ship, entails fighting a formation of Hovering Attackers which are worth 30 points each. The third stage consists of fighting a formation of Demon Flies, which are worth 40 points. Some of the Demon Flies will leave Spy Aliens when killed, which will fall down to the bottom of the screen underneath and try to stab the ship from behind. The only way to kill them (for 100 points apiece), is to destroy the Killer King when he appears. The fourth and last unique stage will see the ship fighting a formation of Rolling Fires, which are worth 50 points apiece and will also occasionally leave Spy Aliens behind when killed. After the last unique stage has been cleared, the four stage cycle will start over again.
Main CPU : Zilog Z80 (@ 3.072 Mhz)
Sound Chips : Tone generator and discrete circuits
Screen orientation : Vertical
Video resolution : 224 x 256 pixels
Screen refresh : 60.61 Hz
Palette colors : 98
Players : 2
Control : 2-way joystick
Buttons : 1
Ginga Teikoku no Gyakushuu was released in November 1980 in Japan.
The title of this game translates from Japanese as 'The Galaxy Empire Strikes Back'.