Daz

Continuity mistake: In the escalator scene when Arnie uses a corpse as a shield, there's a close-up of Arnie's gun firing, and we can see there's blood on the side of the corpse's head. However, in the wider shots there isn't. (00:31:00)

Revealing mistake: When Arnie uses the dead body as a human shield, watch the corpse's mouth - he grimaces every time he gets hit (the squibs hurt). (00:31:00)

Revealing mistake: When Quade shoots Dr. Edgemar, Lori yells "Now you've DONE IT.", and the wall explodes, which is plainly made of foam. Many of the pieces of 'wall' tumble lightly across the floor. (01:05:40)

Nicki

Other mistake: The title 'Publicity' is misspelled as 'Publicty' in the end credits. (01:46:30)

Daz

Plot hole: When Arnie is taking off his woman's head he presses a switch by the ear and the ear comes out. The device reaches right inside the fake head and there would be no room for Arnie's real head. (00:46:00)

Continuity mistake: When Arnie uses the hologram projector in the alien reactor, there is a brief shot of him facing his own hologram image. Note that the gun and the projector switch positions in Arnie's hands - the bloodstain on his shirt's sleeve does not. (01:37:55)

Revealing mistake: In the scene in the Mars Air/Spaceport, the troops are wearing Casio scientific calculators on their wrists. (00:43:50 - 00:46:55)

Continuity mistake: When Doug is running from the bad guys after finding out what was going on from his "wife", he tucks his big gun in to his jacket pocket. When he is running through the scanner, that big gun is now in his pants. (00:28:15)

Lynette Carrington

Revealing mistake: When Arnold jumps through the glass, you can definitely see a change in his face and body shape. (From the stuntman). (00:30:05)

Continuity mistake: When Arnold Schwarzenegger and Rachel Ticotin are being attacked by the giant drilling machine, Arnie grabs a pneumatic drill and cuts the main oil line of the machine, getting the left side of his face and his shirt doused in oil. Yet throughout the remainder of the film, there is no oil on Arnie's face or shirt. (01:39:55)