All things considered, I'm actually kind of glad that a sequel (or, even worse, a series -shudder-) of "The Last Starfighter" was not made. It was a good story when it came out in the mid-1980s, partially because it had a beginning, a middle and an end.
I think one of the things lost today with many action, fantasy and SF films is that they aren't self-contained; instead, they are episodic. While that's okay for some stories ("The Lord of the Rings", "Star Wars" and its two sequels, etc.), there are times when I think Hollywood's over-reliance on properties means we just end up with unmitigated crap: In particular, I am thinking of two of Paul Verhoeven's films, "RoboCop" and "Starship Troopers." Both appeared to be fun, campy action-SF films at first glance, but they both contained darker, more satirical elements nested in them. Not so for any of their follow-ons.
Now, one thing I would not mind is a modern, contemporary re-make of "The Last Starfighter." If nothing else, they could do something about all the alien lifeforms with faces that are arranged in familiar configurations and, even worse, having human eyes (in many cases). Personally, that has always been a pet peeve of mine.