Goofs

The special effects crew failed to rotoscope King Ghidorah's rays when the huge bridge is destroyed. As the shot now plays, the bridge is destroyed by a series of explosions of unknown origin when King Ghidorah simply flies over it.

On the US Naval ship in 1944, the Captain refers twice to another officer as, "Major (Spielberg)". The rank of Major doesn't exist in the US Navy, and the collar device Spielberg wore was that of Lt. Commander.

When the ship's commander calls the sailor "Major Spielberg", the implication is that Spielberg is Steven Spielberg's father. But Steven Spielberg's father, Arnold Spielberg, served in the Air Corps in India, not in the Navy or Marines in the Pacific.

On The U.S. Naval Ship The Captain's Hat Is That Of The Dress White Uniform. In Actuality He Should Be Wearing Either A U.S. Navy Commander/Captain Khaki Combination Cap Or A Tan Garrison Cap With His Rank Showing On The Left Side.

To the individual who stated that the rank was wrong for Major Spielberg on the Navy Ship. Did it occur to you that he could have been a Marine?

The Captain Of The U.S. Naval Ship Has His Collar Buttoned, He Would Have Had It Undone Especially In The Heat Of The South Pacific.

The close-up shot of the English-language newspaper reveals several misspellings, including "shinig", "intreging", and "thould".

When the car M-11 has been driving crashes, M-11 suddenly disappears from the car with a noticeable jump-cut before it explodes.

When King Ghidorah has Godzilla in the death grip, choking him, while he's drooling and charging up his energy, strings are visible on King Ghidorah.

In many flying shots, Ghidorah is obviously an unconvincing, stiff model that doesn't flap its wings.

When Ghidorah is jumping on a downed Godzilla during the fight scene, you can clearly see that Ghidorah's foot bends as he lands on Godzilla. This shows that he was made of some sort of rubber (which also explains the lack of leg movement as he jumps.)

When first studying Ghidorah after returning from the past, the people from the future are looking at monitor bearing a contemporary Panasonic logo.

As Godzilla and Mecha-King Ghidorah plummet into the ocean at the end of the film, the shadow of the cameraman and crane can be seen on the water.

Just after the officials announce that Gidora is attacking Hokkaido, there is a shot of the Atomic Dome in Hiroshima and a shadow of the monster flying overhead. Hiroshima is in southern Honshu, far from Hokkaido. Later, Godzilla does presumably attack Sapporo and then very quickly ends up in Shinjuku.

The time-travel mechanics of this movie are infamously confusing. The plot involves the characters traveling back in time to stop Godzilla from coming into being. Yet when they come back to the present, everyone still remembers Godzilla, even though he's been presumably erased from history.

In 1944, the downed Godzillasaurus is teleported to the bottom of the sea to keep it from turning into Godzilla. It then does become Godzilla when it absorbs the radiation of a nuclear submarine in the 70s, but it's not explained how it remained alive for thirty years under the water.

The time traveling Emmy says she's Japanese, yet she also tells the present-day people that Japan doesn't exist in her time. Somehow no one becomes suspicious of this lie, although it is possible that they took Japanese as her ethnicity rather than her nationality.