Um, so what exactly did happen to that invisible goldfish? Anyone?
It's likely an homage to The Invisible Man, who went insane before disappearing altogether.
Why did Sparky need to be patched up before Victor reanimated him? He got hit by a car, not ripped apart by a mountain lion.
He got hit by a car. Have you never seen roadkill? It can get ugly.
Victor could have taken some of Sparky apart to fix / replace some broken bones or whatnot, and then sewed him back together. He's a corpse technically, and probably won't heal like a normal dog anymore. He obviously had to put some type of contraption in his neck in order to hold the nuts and bolts that conducted the electricity.
Can one make a 3D home movie?
By using two lenses that are eye length apart and putting different colored filters on each one.
Were there textbooks around the time this movie takes place in that would say Pluto isn't a planet?
The movie takes place in nondescript time period that just looks ambiguously like The 50's.
I know Idiot Ball and Drama Ball, but how long was Victor expecting to keep Sparky's reanimation secret from his parents?
He is a child. Child Prodigy maybe, but still a child. They don't always think these things through.
Well, to be fair, at first he did manage to keep it a secret from his parents! They only found out because of unwitting instigators of doom that Victor didn't predict and thus couldn't control.
Why exactly is this movie called "Frankenweenie"? The dog is named Sparky, the owner is named Frankenstein, and there's no "weenie" anywhere... couldn't they have just called it "Frankensparky"?