Astreo - Space Game

It's the year 2020, a countless amount of asteroids has been flying towards the earth for 34 years now. No scientist or physicist has seen them coming. You've been sent back in time to the year 1986, to destroy all of the dangerous asteroids. If you screw up in the year 1986, the entire world will be destroyed in 2020. 

Fly as close to the asteroids as possible without crashing into them, to save the world from a catastrophic disaster! Good luck!