Well, I just felt like telling you good job with it, I like it. (especially the nuke)
Anyway, I could make a few suggestions, maybe you could add some weapons to the city destroyers, probably just some big slow cannon shots for pesky mid sized ships or something, play around and find something cool. Also, I would move some of the sub systems to more exposed places, keep the insta kill laser (maybe add the power system there too, so there's some explanation as to why it went boom) and maybe make it so that if something bumps into it, it doesn't spin out of control. Also, I'm not sure if it's a good idea, but maybe have it so that doing enough straight damage does destroy it, you might have to add a few more zero's to the health to balance it, or maybe just keep it as is, I don't know.
As for the fighter...... DON'T TOUCH THE NUKE!!!!! It's fun having a one shot weapon that can kill all but the most powerful ships assuming I don't miss.
