You are an elite robot. You have meet up with your friend who is another robot name Sera. No one knows what your name is so they called you Unknown. Now, you and your friend must work together to save the earth. The humans have equipped you with a great intelligent brain, unlimited ammo and gun, and much more. In order to rescue earth from the aliens' evil clutches, you must destroy their sacred gem call the "Bloodstone." If you destroy this gem, all the aliens will be wipe out and earth will be save. If you can't....then I guess earth is doom. Choose wisely, young robot, and save earth!