When Newton is playing with the robot arm and the piano you can clearly see wires attached to the top of it controlled by the puppeteers.
The main characters in this film are Johnny and Stephanie, and the film is directed by John Badham. In one scene, Johnny watches Saturday Night Fever on TV. The scene he watches, (and imitates with Stephanie), involves two characters also called John and Stephanie. Saturday Night Fever was also directed by John Badham.