In the dark corners of the infinite universe, the ultimate evil is hiding... The dark forces led by the god of destruction, Bacterian, are preparing to launch a massive attack on the planet Gradius.

With unstoppable power, the Dark Forces threaten to plunge the Universe into total war and complete annihilation. Their aggressive strength destroys the defenses of Gradius, and the surrounding planets fall one after another.

Now, Bacterian's evil reaches the heart of resistance... the planet Gradius.

To face the impending threat, the United Forces of the Gradius universe gather all their warships. Half form a defensive network, while the other half form an offensive team.

However, they are numerically inferior, and the Dark Forces easily shoot down their fragile line. No pilot survives the slaughter...

In a last-ditch effort, the forces of the United Gradius World send two cruisers that had previously been deemed too dangerous for missions: the Space Cruisers VIC VIPER.

The cruisers take off towards the heart of darkness to participate in the battle that will decide the fate of the Universe...