Spy Kids 3D: Game Over [PG] [2003]
Overall movie:  ***
EJW content:  Just a bit (part) of fun

I have no problem with a movie that exists for the sake of its special effects as long as it's honest about it - especially when it has as much fun with them as this one does.  The 3D glasses are definitely retro: unless your head is just right for the "one size fits all" concept, the effect's not perfect (but, don't worry, it's good enough even then - the glasses didn't fit me too well and I still flinched every time the movie wanted me to).  
But the glasses are the only thing low-tech about this movie.  If "movie set inside a computer game" makes you think of Tron, be assured the SFX are much further progressed--and the movie's a lot less serious.  Sure, the fate of the world's at stake, as well as the lives of our heroes, but why get all gloomy and somber about it?  BTW, this is one movie in which Elijah's character does not save the world (not that he doesn't try... oops); that's left to the main players.
And the main players are pretty good.  The kids involved really pull it off, and the big-name stars add to the romp by being willing to poke fun at their own personas; Sylvester Stallone is an absolute hoot as the villain, and Riccardo Montalban has a one-liner toward the end that had me LOL - although you have to be "of a certain age" to catch it.  You'll also catch more jokes if you're knowledgeable about computers and computer games.  My totally computer-illiterate friend didn't laugh at some of the things I did, but she still thoroughly enjoyed the movie.      
With this kind of movie, I'm not really giving anything away by saying the world does get saved in the end--but I was pleasantly surprised at the way salvation ultimately comes, so I'll leave that alone.  
Can you tell I enjoyed this one?  I wouldn't even have gone to see it, of course, if it hadn't been for Elijah's minute-and-a-half onscreen; I was almost considering it a "duty" to squeeze it into my schedule.  I'm glad I did; not destined to be a film classic, but a good 90 minutes of pure fun.  And Elijah's bit is a good 90 seconds (more or less) of pure fun--which is exactly what it's meant to be, too.