Space, the final frontier. Forget the klingons, it's the Dargons you want to worry about. Emanating from their home planet of Dartress, they plan to enslave the universe by running colony ships, or Ringworlds, into unsuspecting planets, conquering them and then moving on again.
Where do you fit in? Well, you've got to stop them of course.
In your supersleek space cruiser, you have to destroy the Ringworlds by means of massive torpedo overkill and then go on to liberate the occupied planets. To do this, you must first capture a shooting star in your tractor beams and release it towards the planet. Succeed in this and the Dargons will be wiped off the face of the occupied planet, though how the goodies survive is another question altogether.
Solar Empire is a marvelously devised game with a wonderfully smooth 8-way scrolling galaxy to run through and some excellent goodies to pick up along the way. If you want to boldly go etc..., then pick up Solar Empire now.