Goofs

The entire movie is founded on a fallacy: All six flags planted on the Moon by the Apollo astronauts have been bleached pure white by the intense solar radiation on the lunar surface. There are no US flags planted on the Moon today.

The Apollo 11 flag is no longer upright on the Moon's surface as shown in this film. It was planted too close to the Lunar Module, and was blown over by the takeoff exhaust.

During the launch sequence, the announcement "Ignition sequence starts" comes before the countdown reaches T-10 seconds, but the Saturn V ignition sequence begins at T-8.9 seconds, with ignition taking place about 3 seconds later.

When Frank Goldwing's spacesuit helmet visor is cracked, he would likely have lost oxygen more rapidly than shown in the film.

When the Lunar Module is flying across the surface of the Moon as they try to find a place to land, the LM rocket engine is not firing, so the spacecraft would crash. The fact that there is no visible flame from the engine is correct; the LM fuel did not produce a flame, but there would have been a glow from the rocket nozzle.

Wasn't it convenient that an Apollo capsule keeps two kid-sized space suits handy, just in case? Maybe the test chimps left them behind?

Keep in mind that all these plot holes were kind of essential to making the movie work at all, and it was an entertaining film.

There are repeated references to Richard Carson's plan to destroy evidence of all the Apollo Moon landings (plural), but only the Apollo 11 flag appears in the film.

Mike Goldwing's initial plan to stow away aboard the Apollo spacecraft would not have worked, since the air inside the Apollo Command Module was not breathable at takeoff (the astronauts wore pressure suits) and the extra weight would have thrown off the projectile motion and burned more fuel than planned. However, this may not matter in the film's context, since the spacecraft takes off prematurely.