Good Idea,
The story is worth while developing more.
The game play not so much. This could easily be a 5 star game by changing and adding a few things.
First make it so the rockets lock on the targets not just shot aimlessly into space.
Second I would add some kind of upgrades that give you purpose. Maybe add a team that attempt research on fusion to bring the sun back to its former glory.
If changes are made then I will replay this game until then its not worth playing.