Ahhh, your game reminds me of Maelstrom -- even though all the sprites were prerendered, the sprites were rendered in 3D and I spent so many hours on it...
I actually did another version 15 years ago, too—incidentally it was my first ever OpenGL app "JAVAsteroids": http://symbolflux.com/statichtml/oldprojects/javasteroids.ht...
Probably the true pioneer in the genre, although not 100% sure.