Monsters spawned from another dimension are trying to make the Milky Way galaxy their personal trashcan. As attempts to defend the solar system fail, the fate of the Earth (that's US people!) and even the universe rests with one man.

YOU are Sam 'Serious' Stone, a legend in our time. Sam is our only hope against these mischievous miscreants and their evil leader, the one we call 'MENTAL'.

The only way to get Mental and save us all, is to use an ancient artifact called the 'Time Lock', to teleport back in time. Don't ask us how or why this is happening. All we can tell you is, this is serious...