Buck Rogers: Planet of Zoom
Coleco ADAM
The Buck Rogers - Planet Of Zoom coin-operated Videogame by Sega (circa 1982)
You're Buck Rogers, and you're on a mission to stop a wandering "warrior-world" called the Planet of Zoom before it reaches Earth. Like a certain moon-sized space station, the Planet of Zoom devastates everything in its path. The Planet of Zoom is controlled by a source ship. Destroying the ship liberates the Planet of Zoom, saving Earth in the process.
The game has only eight stages ("sectors"), with the mothership as the final (and only) boss. Clearing the game puts you on the next loop, with the message...