I used to play this game, in 98, on the mac at school, which involves asteroids and power ups. It looked like something Ambrosia would make, like Maelstrom, but I know it isn't Maelstrom because the game wasn't an asteroid clone like that.
In this game you have the same setup like asteroids except:
The stage scrolls when you move
There's nothing but Asteroids
Once in a while an enemy ship or two will stalk and shoot you
There is a transparent radar display(Different dot colors represent: asteroids,Enemies, and Power-ups)
When you get power-ups the bullets you shoot change colors
So that's all I remember for that game,
Thanks