You are the lone gunner standing between the marauding enemy invasion fleet and Earth. Use your mouse to aim and blast the approaching enemies with the cross-hairs using the mouse. Be careful, though, because you only have so many shots. Gain bonus points for multiple hits and annihilating the bonus ships. Extra cannons earned for every 10,000 points scored. Can you get through every level? Have a blast shooting the Space Blitz Cannon!