Corrected entry: When the family is running around trying to settle down the big Adam, Adam picks up Nick. From the back view, Nick is obviously a doll.
Corrected entry: The whole plot of this movie rests on the fact that Rick Moranis' character and the team of scientists are having difficulty enlarging matter. Yet at the end of the previous film, Rick Moranis' character had used his original shrinking machine to enlarge a turkey to giant size for the families to eat and had blown up a bone for Quark. And further still, at the end of this movie he uses the shrinking machine to enlarge his wife with no problems at all. So it is established that his original machine CAN enlarge things, therefore why is he at Sterling Labs experimenting to try and do something he can do already? Let alone spend time and money trying to make an overly complex, immobile machine that takes multiple technicians to operate?
Correction: 1) They are not having trouble with the science, but rather re-creating the results of his homemade machine on their larger version. 2) His machine is in his attic, and is likely something he might want to keep. He simply is assisting them in building one that they can use for themselves.
Correction: Not true. Watch the "making of" in Youtube: It is a stunt in extra large clothing shot from a specific angle.