The ostensible sequel to the venerated Star Raiders actually had very little to do with its creator Doug Neubauer or the franchise. Originally called Orbital, the project was later intended by Atari to be a tie-in game with The Last Starfighter, and the plot of protecting the home planet from being bombarded while trying to destroy the various enemies seemed to have something in common with its intended property. With the popularity of Star Raiders, though, it was decided to tack on a Zylon theme to everything. Perhaps some changes were made in the game itself, but both the game and the film didn't do so well.
Here is a profile of The Last Starfighter version of the game, which was never officially released: