The distant planet of Gunstar 9 has enjoyed a peaceful and prosperous history, so the last thing the inhabitants expected was an alien attack. And now it has happened. With the military rendered useless by the attackers, the planet is in need of some GUNSTAR HEROES to save the planets and prevent the total annihilation of Gunstar 9. This is where you come in, as one of two brothers, you must destroy the evil that has infiltrated your planet before it's too late. You've got a 360-degree firing radius, and you're going to need it to handle the hordes of enemies that will bombard you with all kinds of weapons and traps. Whether you play by yourself or team up with a friend, the fate of Gunstar 9 is in your hands!