F/X2 was actually a good sequel. But I think that's because it is very much like the first movie. And, F/X itself was a great movie because of the idea of a special effects artist trying to get himself out of a mess. Rollie Tyler (Bryan Brown) is now a toy inventor, having retired from the special effects business. His girlfriend's ex-husband, a cop named Mike, employ's Rollie's special effects expertise to set up a sting operation. But, something goes foul and the cop winds up dead. Like F/X 2, Rollie becomes once again involved with crooked cops and has to solve the whodunnit. And, part of what made the first movie great, too, was Brian Dennehy as detective Leo McCarthy, who Rollie Tyler calls on for help.
As far as the story goes, it involves a bigger scale of corruption in the law enforcement circle, but the movie is just as enjoyable. And, you still get to see Rollie Tyler using his special effects abilities, which I always thought was the best part of the first one. If you have seen the first F/X, it's probably very likely you'll like the second one. It's one of the few movies I have seen where I can say that the sequel was pretty good.