Gradius Union is a heroic organization appeared in both Gradius spin-off mobile games: Gradius Neo and Gradius Neo Imperial, when at least 2000 years have passed since the last Gradius Empire-Bacterian war.
New Fighters, New War, New Threat
In this new timeline both Gradius Empire and Bacterian Empire don't exist anymore. Gradius Union sent their variant of Vic Viper to enter the war against the villainous Lars Empire, a new hegemonic villain empire. Then Gradius Union's goal is to stop the forces of Lars Empire and their emperor who was inspired from the original Vic Viper pilot named James Burton, or Emperor Lars XVIII.
After the Union's agent, Force Viper, single-handedly crushes Lars' forces and liberates the occupied territories, the starfighter successfully infiltrates into the Lars Empire base, destroys Central Server, the commander of Lars Empire, and put an end to the empire's hegemonic ambition of universal domination... For now.
Force Viper originally had been found by Lars Empire that had been collecting and amassing ancient technologies from the Gradius Empire to launch a global conquest. When Lars Empire was about incorporate the ancient starfighter into its military, the starfighter was hijacked by the spies from Gradius Union. After coming to the Gradius Union Force Viper became the spiritual successor of Vic Vipers, legendary starfighters from Gradius Empire era.
Force Viper has to undergo 5 perilous journey to liberate planets and sectors occupied by Lars Empire and defeat Lars Empire.
- Stage 1: The Neutral Zone - this is an area a little further away from Gradius Union-Lars Empire war frontline. There is no terrain, it is composed purely of space-born air battles. Commanded by Satellite Core.
- Stage 2: Asteroids Zone - A military installation with Moais where Bacterians set their base here. To get to Lars Empire Base Force Viper has to go through here. Watch for fragmentary asteroids. Moais here are backgrounds so they cannot be destroyed. Guarded by Crystal Moai which can be destroyed.
- Stage 3: Lars Empire Fleet - the powerful fleet of the empire awaits. Duel with Gigantic at the end of the stage.
- Stage 4: Space Highway - There would be an extremely fast scrolling section exists. Once Force Viper successfully navigates through the speedy section Lars Empire would be on plain sight. But, defeat Ogre Shield before progressing further.
- Stage 5: Lars Empire Base - The headquarter of Lars Empire. Central Server, the leader of Lars Empire, resides here. Force Viper in this stage can choose paths.
- Lars Empire was already in a bad shape when Force Viper is launched to repel the Empire forces due to defectors within the empire. The defectors escaped with Customized Big Core, and Lars Empire sent out its pursuers to kill the traitors. However despite the odds, Big Core Custom piloted by the defectors succeeded in breaking through and destroying good portion of Lars Empire military set out to pursue them. This is the story of Gradius NEO Imperial.
- However, just as the Big Core Custom succeeded in escaping from Lars Empire, it runs smack into Force Viper and, in a tragic case of mistaken identity Force Viper, thinking the Big Core Customer as just another war machine of Lars Empire, destroys it.