My Deceptive Memories of Star Frontiers

Back in my school days, when we were playing pretty much every rpg game we could get our hands on - one of them being TSRs Star Frontiers. My memories of this rpg are vivid: I remember the illustration of the amorphous Dralasite with its eyes that looked like textbook renditions of cancer cells (I immediately called dibs on that one); I remember the characters on the cover, expecially that kind-of-cool, but also kind of revulsive ape-bat creature that turned out to be a Yazirian (my best friend called dibs on that one, which figured, since his favourite childhood plush toy had been a little smiling monkey in a striped tee); I remember the big city map with its ugly, squarish design, that, I think, was supposed to show a spaceport city; and I remember that, when you held the boxes lid against the light, that it was actually from a D&D red box and they had only pasted the Star Frontiers cover on it! (What had happened there? Had they produced too many D&D boxes and saw no choice but to publish another rpg to make use of them? I guess that's not how it went, but it would make a good anecdote. Also, I'm writing about the German edition of Star Frontiers here, which was called Sternengarde, so don't be surprised if you find nothing of that kind when you hold up the lid of your original Star Frontiers box).
Anyway, my memories are so vivid and create such a deep sense of familiarity, I naturally assumed that we must have played the hell out of Star Frontiers and loved it. (I even claimed just that recently on social media).
However, thinking about it a little harder, I actually can't remember playing it.