Gaiares

It's the year 300x. The Earth has been ravaged by careless humans, leaving an uninhabitable, polluted wasteland. The space terrorists, Gulfer, plan to harvest the pollution to make some sort of garbage weapon. The good guys, the Leezaluth, aren't happy about that, so they decide they have to blow up the Earth before Gulfer gets at it. They give Earth an ultimatum: destroy Gulfer or Leezaluth destroys Earth. (mobygames.com)