Actually, other than that one transportation device, the movie is about 100x more likely than the original. After all, which is more likely - humans build a device that travels through the Earth, or radiation on Mars turns humans into a variety of mutants, and aliens build a machine that creates a breathable atmosphere on a planet with a fraction of Earth's gravity. Not to mention action scenes that wouldn't work with Mars level of gravity. I'm assuming the tunnel was created before human civilization fell, so to speak. But then, assuming this is the case, it is quite a coincidence that the only two habitable areas on the Earth are connected by the thing. Someone made a comment that this one follows the short story more than the original. I don't know if I agree. Yes, the story didn't have Quaid (actually Quail in the story, but understandably changed considering who the VP was at the time) go to Mars, but he did go there before his Rekal trip. Synopsis for the story - so spoilers! As you can see, other than the very basic story points, neither movie really follows the short story.