The fire effect when crashing is quite convincing, good job!
Also, the artwork / animation of the little person in the spaceship looks really good. Wonder which tune they are rocking to? (obligatory "please add adlib music" nag)
Is the planet surrounded by a solid sphere? I bounce off the "top" of the screen as if there was such a thing.
The hitbox for the asteroids is quite small. Couldn't the little person salvage cloth dryers and build a kind of "shield" out of the salvaged ones, so that hitting an asteroid reduces the shield? (e.g. 1 shield added per clothes dryer salvaged, 1 shield removed per asteroid hitting the ship).
Also, my newfangled VGA card is heavly unused by this, hope there will be a mission disk that adds VGA support, a speech pack and adlib music ;)