I'm usually pretty good at "remember that game" when friends ask me, but there is one particular obscure game for Apple II that I remember but could never find again. Maybe one of you knows it?
It was a shooting game and it had two distinct phases. One was in space and the second was on a planet. While I don't remember the gameplay that much, I remember that when you lose the screen shows two giant eyes looking left and right, as if the alien are mocking you.
So it was not exactly a Space Invaders clone, it had a few more things to it to make interesting. There was some simple art in background to make it more interesting, to make you feel you are in space or on the planet.
If Im not mistaken in the space half you move vertically and in the planet half you move horizontally like in space invaders.