The Martian is a darned fine film, not merely one of a tiny number of hard-SF films that gets the numbers right* but a movie that gets the characters right, too, from the habitual fitness of astronauts through a wide array of geeks, bureaucrats -- and geeks-turned-bureaucrats -- and even to a few "regular people," spouses and TV reporters. It's a big cast and we spend a lot more time with Matt Damon, trying not to die, alone on Mars, but they're part of what makes the film work.
Another part -- a big part -- is the planet itself. This is a film that knows its roots. If you remember the 1956 book The Exploration Of Mars (Willy Ley, Werner von Braun and Chesley Bonestell), The Martian's "Ares II expedition" looks like an updated version of it, in a setting that is more than merely evocative of the Bonestell paintings (with, I think, a touch of Maxfield Parrish: that light!). Mars itself is one of the film's characters, from vast, red-sand landscapes to terrifying storms. Will Mars really look that way to the first explorers to see it for themselves? I don't know (and it depends where they land), but I doubt it will be all that different. (There's a more-overt Bonestell connection in the film, too.)
The movie is a celebration of problem-solving, of the will to survive and the wit to make it happen. Some reviewers have complained the plot relies too much on coincidence and luck, but I disagree. Oh, there are a few "stretchers" and one point where the odds are so far out of whack that you'll have to power past it (trust me, by then you'll be up for it), but most of the "luck" is the kind that comes to the prepared mind, already working on the problem -- the kind of intense geekery that you're not going to get if you've never Been There or Done That, the sort of thing that if you don't work in some kind of science or applied technology, you may never have experienced the, "oh, of course" moment of realizing a totally orthogonal solution will work.
If you like SF (and especially if you find most SF films disappointing), if you like stories where the good guys win through determination and intelligence, if you're a techie or boffin of any sort -- see this film. You'll be glad you did.
* Despite the dated style, Destination Moon springs to mind, and the more biologically-inclined Gattaca. Parts of 2001 as well. Past that, your cinematic SF choices are mostly horror (e.g., the generally well-done Alien films) or various flavors of space-opera gee-whiz fantasy that play very fast and loose with physics and science in general past the handful of impossibilities essential to the yarn (which was my problem with Serenity, which went much worse that way than Firefly) and most of which also ignore or mock the conventions or written SF. Exceptions are incredibly rare -- Predestination (the film adaptation of Heinlein's All You Zombies) is striking for exactly that reason. The various Philip K. Dick books that have been translated to film have held up well. Star Wars and Star Trek films are good fun with reasonable internal consistency, but they're fantasy space opera: stirring stories you could probably file the off details of and reshoot as cowboy, war-story or pirate films without much effort.
6 months ago