Goofs

Quaid touches walls, switches on lights, and grabs Lori's arms to explain that he is being hunted by spies, then shows his blood-covered hands to her, yet there is no blood on her arms or the walls.

During Quaid's fight with Lori in the apartment, Lori slashes Quaid in the chest with a knife. After the fight, the cut marks on his shirt are mysteriously gone.

When Richter and Helm are waiting by the hotel's service elevator for Lori to bring down Quaid and realize something is wrong, they run over to a normal elevator and go up, yet they end up coming out of the service elevator on the sixth floor.

During the escalator shootout, Quaid uses a bystander's body as a bullet shield and the body is shot to pieces; Quaid then throws the very bloody body onto Richter and his henchmen to slow them down. Moments later, as Richter and his henchmen chase Quaid into the train station, it is obvious that they haven't a drop of blood on them, despite the fact that the bloody corpse landed right on top of them.

At Rekall, when Dr. Lull is questioning him about his dream girl, Quaid's request of "sleazy" and "demure" are highlighted on the monitor before he says them.

in the construction scene, many construction workers operating jackhammers are shown to be wearing hard hats and ear protection for obvious safety reasons. Doug and Harry are wearing neither.

The exterior shots of Mars depicts the Martian sky as having either a dark orange or deep crimson color to it. In reality, the Martian sky is not as deeply colored and is actually a light pink or light orange color at times. Furthermore, the night sky on Mars is shown to be just a slightly darker red/orange than the day sky, when in reality the Martian night sky is just as black/starry as it appears on Earth.

Dissolving ice either by evaporation or hydrolysis would not provide a breathable atmosphere. Evaporation only gives you steam, which is not useful oxygen. Hydrolysis would give you an atmosphere of hydrogen and oxygen which is highly explosive! Any spark or flame would pretty much turn the gases into water (back to ice), killing anything in the area with the highly exothermic reaction.

Due to the small size of Mars, there isn't enough gravity to retain an atmosphere. So even if an atmosphere were artificially created, it would float off into space and all those people would still suffocate.

Towards the end, Quaid & Melina are flung out into the raw atmosphere of Mars, and their eyeballs are near about gorging out of their respective sockets. Tongues too. But when the 'oxygen-rich' atmosphere hits them, they both turn back to normalcy again. In real life, the damage to the eye, retina, pupils etc, has already happened, and they will just not pop back into normalcy(given the theory of a normal atmosphere in the film). All veins and arteries would also swell and be malformed forever.

At several points in the film, characters either shoot at the glass in the Martian domes and crack it, or are advised against doing so. It seems odd that this futuristic, space-faring culture would not install bulletproof glass in these domes, given the dire results of the windows being destroyed. Throughout the movie, several references are made to Cohaagen constructing Mars Colony by cutting corners, building cheap domes, and pocketing the cash for himself. Also the cheaply-built domes not adequately filtering out the solar radiation explains the mutant population on the planet.

It would in reality take at least five months to reach Mars from Earth via the fastest means possible, yet the movie assumes it only takes a matter of hours or days. This artistic license has been taken in a number of other sci-fi productions, going all the way back to A Trip to the Moon (1902), presumably on the assumption that in the future, new technology will have been discovered that allows for faster space travel.

No one at Rekall seems to have considered the psychological aftermath of implanting "ego trip" memories, of customers who will vividly remember being star athletes or violent secret agents and suddenly aren't, of the PTSD and other mental breakage that would result. They have already wiped more serious incidents under the rug without trying to remedy their causes, so it's clear they don't care enough about their customers to consider something like this.

When Quaid is removing his woman mask, a part from the ear extends that goes in way too deep for his actual head to not be in the way.

The security guards wear some kind of portable computer (display and keyboard) on their wrist. During the fight at customs, a close-up reveals that it's just a Sharp pocket calculator taped to a glove.

When Richter is shooting at Quaid from the top of the escalator, he uses a human shield then turns and throws the body at the goons on the escalator below him; you can see the stuntman's eyes open and face cringe as he flies through the air.

When Quaid is in the slum hotel room, the phone in the room starts to ring. The person on the other line is a 'buddy' of his from the agency on Mars who says that he was supposed to find him if he ever disappeared. After Doug wraps a towel around his head to muffle the bug signal, the friend tells him to go to the window to see a suitcase that he was going to leave for Quaid. The 'friend' on the visual phone looks up to the right as though he's looking up to Quaid in the hotel room. In fact, Quaid's 'friend' has to turn to the left and look up, not right as shown on the videophone.

When Quaid and Richter are fighting on the elevator, Quaid throws Richter into the back of the elevator and it wobbles, revealing it's made of soft material.

After the fight at The Last Resort, Richter jumps through a glass wall. The glass doesn't break to small pieces, so it was not tempered, laminated glass, as is a front glass of a car. So, it was real glass, and Richter should have got hurt at the head from the impact, and he falls on glass pieces, so he should have got cut or bruised severely, even dead.

They claim no animals are harmed in movies, yet in the 2010s it has been revealed by Hollywood insiders that animals routinely get hurt for movies; this is the case here, as seen when Arnold Schwarzenegger himself violently swipes a group of rats from a high platform onto the ground below. The same happens about 25 minutes from the end, when the bad guy kicks a tank, spilling several huge goldfish on the floor, which are then seen gasping for air or, rather, water.

When Benny gives the other taxi driver the finger and says "Eat this!", the audio is not in sync and he is saying something else.

While Doug writes Melina's name on a piece of paper, the sound of the writing isn't in sync with the hand movement.

At movie time mark 1:03:43, when Dr. Edgemar and Mrs. Quaid are with Douglas Quaid in his room at the Mars Hilton Hotel, lighting equipment for the scene is visible as a reflection on the double sliding glass door mirrors.

As Lori exits her marital bedroom, just after her image is visible in the mirror, a crewman wearing a white t-shirt is briefly visible in the same mirror.

Person's head visible behind bed during first sex scene.

Before Quaid opens the Johnny Cab to escape Richter and his assistant Helm, you can see - in the 4:3 version - the tracks of the camera dolly.

The two moons of Mars appear in several background shots, but they are incorrectly depicted. They are both shown as being much larger than they would appear in real life - Phobos would appear to be about a third of the size of the Earth's moon, and Deimos as little larger than a star. In addition, Phobos orbits Mars faster than Mars rotates, so it would appear to rise in the west and set in the east, and should have moved visibly with respect to Deimos even from one shot to the next. The two moons are always shown in the same relative positions, however.

Richter and Cohaagen have a videophone conversation in a car. Unless they have an Orson Scott Card ansible, or some other future technology which can overcome physical laws, one cannot have a conversation with someone on Mars from Earth without a delay of about 12 minutes between transmission and reception of signals. The speed of light and distance to Mars prohibits a real-time conversation.

The soldiers are all wearing what appears to be bulletproof vests, but they don't seem to stop anything.

When Richter and his crew are waiting to ambush Quaid at the reactor, they shoot at him from opposite sides not knowing that it's Quaid's hologram. This means that the bullets are passing through air (unless it's a bullet-absorbing hologram) but none of the shooters facing each other gets wounded, nor killed.

Later, Melina uses the hologram to get two bad guys to shoot each other through her hologram.

When Richter and his henchmen have Quaid dead to rights in the Johnny cab spinning around in circles, they pump nearly a hundred bullets into the cab, breaking the windows at the same level as Quaid is sitting, yet he doesn't suffer even a scratch.

The men from "The Company" know that Hauser/Quaid is going to Mars (the briefcase video is still playing when they catch up to him on Earth and it's instructing him to go to Mars) and they are shown arriving on the same vessel that transports him. Unless the trip to Mars takes minutes or hours, they would have been able to search that vessel and locate Hauser/Quaid.

This also presents the problem of why the passengers from Earth (which, given his size, Hauser/Quaid could only be one of a few) were not taken to the side either on the ship or in the customs area on Mars. Or why scans could not have been done on the ship to determine Hauser's/Quaid's identity as his disguise simply obscured his appearance.

Inside the reactor when Quaid turns on the hologram, none of the solders are shot on the other side are shot as they release there clips on the hologram.

In addition to the fact that some of Richter's men would have shot each other when they're firing at the Quaid hologram (since they're position in a way that the trajectory of their shots would impact each other as they pass through the hologram's nothingness), none of the troops or Richter seem to notice during the 15 or so seconds of shooting that there are no impact wounds or blood from the high-caliber weapons "hitting" Quaid. He does fake that he's being gravely wounded and then shot to death but there's no way he could fake having dozens of gunshot wounds, especially since it's clear he isn't wearing any protective body armor or anything that would otherwise explain him getting shot with no visible damage.

When Tony tells Kuato that the ventilation system is turned off, Kuato replies that Melina and Quaid arrived. Melina (and some of the other rebels) knew him as Hauser. Since "Quaid" is a new identity and not even Melina believed his memory was erased when they met earlier, it is strange that Kuato mentioned his fake name (especially since the two never spoke at The Last Resort when he came to see Melina and thus, he didn't introduce himself as "Quaid" to Kuato).

When Quaid is running through the X-ray hall, a couple of guards quickly approach him, trying to arrest him for carrying a weapon. But after he escapes crashing through the glass the guards suddenly become relaxed and let him escape, and 2 seconds later they also let Coohagen's armed men freely run past them as if it's nothing.

When Quaid throws the bloody corpse of the man he had been using as a shield on the escalator, the stuntman can be seen opening his eyes and launching with his hands towards the actors climbing up the escalator, but his character is supposed to be long dead.

When Richter and his soldiers surround the holographic decoy of Quaid and open fire the two groups of soldiers are facing each other with "Quaid" in the middle, a prime situation for friendly fire. This is putting both groups directly in each other's line of fire, a mistake a trained soldier would never make, they'd wind up shooting each other just as much as the target in the middle. Plus since their target is a hologram their bullets should have passed right through it, yet none of the soldiers get hit by friendly fire.