Instead of everyone having cellphones and hybrid cars in 2000, everyone has giant spaceships that dwarf the tiny 1939 rocket.
These are the second moon men in comics, after the one-panel cameo in New Comics #4. The moon men have highly advanced science, able to pull a "planet" out of its orbit and aim it at Earth. It's unlikely a planet, of course, as comic books seemed to use all astronomical terms very loosely. Perhaps a meteor?
The raygun that stops all mechanical functions seems a cliche, yet is curiously still missing from H&H.
Wing uses the Improvised Landing Aviator stunt.
(Scans courtesy of Digital Comic Museum)