Galaxy Patriot

You are a Galaxy Patriot, a mercenary, moving from planet to planet protecting the defenseless from evil alien attackers bent on destruction.

Using your defense shield you protect the planet from waves of alien laser shots and eventually are forced to face the mother ship of each attacking alien race.

As the planets don't have their own weapons, you use your shield to deflect the attacking mother ship's lasers back to destroy them. All the while collecting coins as payment.