Taking place in the distant future, Earth's people starts their search for new planets to colonize, specifically those similar to it.
Commanded by the mysterious Shienryu, the alien space fleet invades the Mother Planet and constructs fortresses across the world, destroying and replacing any established human influence.
Survival is a great emphasis in gameplay as enemies will fire blankets of pulse shots across the screen, some larger than others and some taking on wide intricate patterns.
When player starts a game, the initial fighter fires vulcan with slowest movement.
When a player loses a life, the game continues at the last reached pre-defined checkpoint with firepower collected by the last fighter at slowest speed.
[1] Bomb type and weapon colour are changed depending on the pilot: A fighter can fire strong but concentrated shots, or weak but widespread shots, depending on the button pressed.
When an enemy is destroyed, its score is multiplied between 1 and 256, depending on the frequency the fighter was firing at the time of destruction.