Gunstar Heroes

Once upon a time, Dr. Brown managed to defeat a mad android known as Golden Silver, who tried to suck out the energy of the planet G-9. Dr. Brown extracted four Mystical Gems, the android's power source, and sealed them on one of the planet's moons, where it was guarded by the four Gunstar siblings. However, years later, a dictator named Smash Daisaku kidnapped Gunstar Green and brainwashed him into telling him where the Mystical Gems were. The dictator is now close to reactivating Golden Silver...