"The War of the Planets" title is actually borrowed from the 1955 classic "This Island Earth", which was later edited down into a 9 minute short film and released on Super 8mm as "War of the Planets" by Eugene W. Castle and his Castle Films Co.
The main inspiration for "The War of the Planets" was the 1953 version of "The War of the Worlds". The film also draws references from "This Island Earth" and "The Day The Earth Stood Still", including the names of the two lead characters - "Rex" after actor Rex Reason (This Island Earth), and Sylvia, after the character that Ann Robinson plays in "The War of the Worlds".
The 'war machine' in "The War of the Planets" is actually a G.I. Joe toy jet cut in half and turned around backwards. It was painted copper to mimic the war machines from "The War of the Worlds". The flying saucer was made from a plastic light fixture and a car stereo speaker.