What's the explanation for it all being real? If it was fake, it would all makes sense, how everything happened just as advertised, how blatantly cliche-filled bits of it are, even the plot holes could be handwaved with "Quaid isn't all that smart". But if it is, then it's just a cliche sci-fi action film.
There are two major factors that point to Quaid's experiences being real, at least in my opinion: (1) The fact that he dreams about Melina long before he meets her "for real," and (2) The dialogue between Dr. Lall and Bob about how Quaid can't simply be acting out his ego-trip because it hasn't been implanted yet. I personally think the whole thing being a dream is the more plausible explanation (mainly because, as you say, it explains away all the junk science like the core of Mars being made of ice), but the second point is particularly damning; why would Rekall bother implanting any of that if he's not conscious to see it and it doesn't seem to have any bearing on the rest of the movie? On the other hand, it could be they stuck that bit in Quaid's mind just to make the dream that much more convincing; of course it's all real, because Rekall wouldn't lie about screwing up, would they?
Or put another way, when Quaid is giving the details about his "fantasy vacation", he was conjuring up repressed experiences from his subconscious. The device keeping his memories repressed then shut off temporarily (possibly because it was supposed to respond to similar external stimuli) which is why he had that outburst that resulted in his getting tranqed and put into the cab.
I think the clearest evidence to it being "real" is that the audience is shown things and conversations that Quaid can have no knowledge of. Parts of the film simply don't happen from his perspective.
On the other hand, these could essentially be the Rekall equivalent of 'cut-scenes' to enable his mind to fill in the gaps of what's happening, thus making it more plausible.
I've always thought it was real because of how Rekall is supposed to work. They implant memories, not actual experience. If it worked the way it was supposed to for it to be fake (but going wrong), Rekall would just be a glorified virtual reality. The story of something going wrong in the middle of his Rekall treatment that would leave him lobotomised, but not before experiencing his new memories in real time, just doesn't make sense!
The director has stated that both interpretations fit the facts, and refuses to say which is true. Under the "all just a dream" explanation, Melina was simply constructed right on that readout while he describes the body type for the girl, and his own mind fills the gaps with the image form the dream. The "failed implant" was simply part of the failed memories. And it is possible to witness things from other perspectives in dreams, though it admittedly isn't common, and usually the dreamer reacts to them when it happens.
Probably the best evidence of all that it's for real is that, if it was just a scripted pseudo-experience, Rekall wouldn't have dared to include so many Mind Screws in the adventure's plotline. Else, it'd be leaving itself open to lawsuits from people whose relatives came out of the device convinced they genuinely were memory-wiped spies!
This cannot be fake in any way. Suppose everything that happened in the movie, tons of people dying, and Quaid personally triggering the terraforming process on Mars, was implanted by Rekall. How would the people at Rekall handwave the fact that none of it really happened, despite claiming that the memories they implant are as real as the, um, real memories?
They're advertised as seeming and feeling real. Obviously, if they include over-the-top fantasies (like being a wizard with magical powers or, well, a Double Reverse Quadruple Agent) they don't have to worry about your memories not jiving with reality. You're probably expected to still be aware they were implanted. Heck, not letting you retain the knowledge that you chose to let then screw with your mind would probably be a very bad idea, from a liability standpoint.
By this theory, Rekall is basically a sci-fi equivalent of a video game-stroke-theme park ride-stroke-action film, all done with virtual reality. Notice how things start off fairly small; the procedure at Rekall doesn't quite work, they find something slightly wrong about Quaid, when he leaves things seem like they're normal but everything just seems a bit... off. Then it starts getting bigger; his best friend and his wife are revealed to be not what they seem. People start hunting him. And so on and so on, it gradually and slowly escalates until eventually he's on Mars with triple-breasted prostitutes and mutant super-intelligent fetuses and ancient alien technology based in the frozen core, and he's not questioning it because it all seems so real and natural. And then when it ends, and you come back down, you might be a little disorientated for a while, but eventually you'll just accept "Okay, it was just a ride — but what a ride!"
And it can't just be a cliche sci-fi action film because...?
Why would the martians build a device like that? They would have little to no use for the foreign air!
If I remember correctly, the builders are only ever referred to as 'aliens', not Martians. Perhaps they were previous colonists who never got round to turning on the machine for some reason, rather than indigenous to Mars. Alternatively, Mars may once have had an Earth-like atmosphere, lost it through some disaster, and the builders were attempting to restore it, but died out or left first.
As mentioned above they're described as "aliens" rather than Martians and probably breathed a similar atmosphere to humans. Presumably the atmosphere machine was part of a failed attempt to colonize the planet.
Or maybe they did use the machine once to give Mars an breathable atmosphere, but then died out or left sometime after that and the atmosphere eventually disappeared naturally while the machine recharged itself and waited patiently for the next person to come along and press the button. It is certainly more believable than the idea that aliens built such a giant machine and simply never pressed the button.
The novelization suggests (and the movie does too just... vastly more sparingly, and you'd have to make much bigger leaps of logic to get there) that the aliens lived underneath the surface, in facilities like the one the reactor is housed in. The reactor was an attempt to make the surface habitable as well.
Paul Verhoeven is almost indisputably a sadist. Why else would he force us to watch oxygen-deprived characters suffocating to death for what seems like several minutes, when in reality that would not be the case at all? (Wouldn't anyone exposed to the vacuum of space immediately turn to puree and be dead in about ten seconds?)
Actually, the idea of instantaneous death in a vacuum/hostile environment is an example of Reality Is Unrealistic. Verhoeven actually got it right; in a vacuum you can survive for up to a minute, but it wouldn't be pleasant. On Mars you'd be able to last a little longer, if only because there's some pressure.
Well, Verhoeven only slightly got it right. Mars has a pressurised atmosphere so someone exposed to it certainly wouldn't balloon but given that it's mainly carbon dioxide they would asphyxiate, if they didn't freeze to death first. Regardless, what you see in Total Recall isn't even remotely realistic.
The pressure difference between Mars' atmosphere and total vacuum is very thin. Basically, on a scale of 0 to 10, where 0 is vacuum and 10 is Earth standard, Mars rates about a 0.6.
The alien device creates suposedly air by decomposing water. But where doesn the nitrogen come from?
Wouldn't that mean that Mars wouldn't have a blue sky? Theories may have changed since I heard this, but I was told when I was a kid that the sky is blue because the nitrogen that makes up most of our atmosphere scatters the blue light around.
It's a massive alien reactor from thousands of years ago at the very least, I think it's safe to say they probably don't know everything about how it will actually create a usable atmosphere.
There is technology that can implant memories and no one has thought of a better way to use it than as a "All In Your Mind" Vacation Package?!
Seriously, this technology could revolutionize education. (For example: 10 years of Med School compressed into a Total Recall Program).
The ability to give entire lifetimes of experience in varied professions in different times and places could be very useful to a society, effectively allowing it to be full of Omidisciplinary Old Masters from the ground up.
It might not work that way. Giving Quaid memories of being a badass superspy, for instance, won't necessarily give him a black belt in kung fu. A lifetime's worth of memories, or even just the med school part, might be dangerous or otherwise unfeasible.
Who says they aren't using the same technology for educational purposes? Quaid never goes anywhere near a school, so for all we know they could all be using the same equipment as Rekall.
As far as we know, the memory implantation process might only be able to feature two weeks' worth of memory. That's why it's limited to vacations and stuff and not education, because more information wouldn't fit on their tapes and doing multiple sessions would fry your brain somehow.
Actually, the agent mentions that you can put more then two weeks on it, it just costs more. However, we don't know how much stuff you can put on a single implant, so the limit could be anything from a month to a lifetime.
The implants would have to include a lifetimes worth, to create Quaid as a distinct person.
Yes, but notice they don't exactly have him living as a surgeon or a chemist or a programmer or anything. He's a low-level construction worker, and while that would require some specific skills they're not exactly eight-years-of-university type skills. Thus it can be inferred that the memory implantation devices either can't generate skillsets from nothing or it's very limited in the types of skillsets it can implant.
Consider also that the problem of 'synaptic embolism' is implied to be a fairly common one; certainly the Rekall boss seems more than a little bit shifty and quick to change the subject on that one. Most reputable educational facilities would likely hesitate before approving the widespread use of an 'educational' tool that posed a good risk of essentially lobotomising a good proportion of their students.
Although I'm definitely more of the opinion that 'it was all real,' even when I saw it in theaters, I was always rather disturbed how easily an ordinary blue-collar construction worker (like Ahnold) immediately slipped into committing multiple acts of violence without hesitation, including killing complete strangers, and never stop to feel any remorse, much less question how out-of-character his life had become at the drop of a hat. "I'm Quaid! I must be Quaid! Uh-oh, I need to shoot my wife now."
Deep seated memories in his subconscious, muscle memory from training and the adrenaline rush from being put into danger. If he really was a soldier/secret agent, he already knew how to do those things and was unconsciously calling up his existing experience.