It was a vertical shooter where you fought waves of abstract enemies. But each wave had only 1 type of enemy. The screen didn't scroll, so it was a bit like Galaga or Galaxian. On the even numbered waves, instead of fighting enemies you negotiated in narrow tunnel that zig-zagged and tried to avoid walls. There were no power-ups. The graphics were simple but colorful.
The title might have had the word "blast" or "blaster" in it. But that could be a red herring since searching those words on Moby Games does not find it. Any guesses on this one? It may be too obscure. I had it on a disk where I had also copied the DOS version of Phoenix.
Good times.
