Monsters spawned from another dimension are trying to make The Milky Way their personal trash can. As attempts to defend the solar system fail, the fate of the Earth, and even the universe, rests with one man. YOU are Sam 'Serious' Stone, a legend in your time. Sam is our only hope against these mischievous miscreants and their evil leader, Mental. In practice, this translates into adrenaline-pumping, non-stop alien blasting action, as Serious Sam throws whole waves of monsters at the player.