Mostly it handles the genre well, mainly because the premise is simple and does not require much world building. In the future Earth has been devastated in a war with an alien race known as the Scavengers. Most of humanity has either fled to Titan or lives on the TET, a giant space station in orbit above the Earth. Jack (Cruise) lives on Earth and works maintaining a fleet of robotic drones which protect devices which harvest Earth's water for fusion power. Jack has strange dreams of his life before the war with the Scavengers which his colleague Victoria (Andrea Riseborough) refuses to discuss with him. When a human space ship from the pre-Scavenger war days crashed on Earth Jack is surprised that the drones kill the human survives. He saves one woman who resembles someone from his dreams. Together they must find the truth to Jack's past and real purpose of the TET.
Oblivion is filled with motifs familiar to hard sci-fi. There are alien invaders that make noises reminiscent of the Combine's radio chatter from Half-Life 2. Computers up to no good, more than a little like 2001's Hal. Matrix-style resistance leader encouraging the hero to discover reality. Flyers that behave like Dune's ornithopters and drones that appear to have been designed by Aperture Science.
All this is well trodden ground for sci-fi fans, but the question is: can the story compare with novels or games which have a lot longer to develop their characters and world? The short answer is no. The story behind Oblivion (despite being engaging) is not as nuanced as that you find in a novel. It might be slight unfair to expect it to be, but the need for action sequences and the mainly linear narrative prevent Oblivion from becoming a world the viewer can really feel they inhabit. There are too many unanswered questions, which I will not go into here for fear of spoilers, but a bit more world building and explanation would have made a big difference. That said it is already a long film and is well paced, what the story needs could be the undoing of the whole film.
As an action adventure film with sci-fi elements Oblivion works well. The story is exciting and immersive, the performances are good and the special effects are very good. The sound design is especially strong, adding to the tension and brilliantly characterising the non-human characters. The movie uses the entire film-makers toolbox to bring the sci-fi world to life which is one of the film's great strengths. Another is that the high budget of a Hollywood blockbuster allows for the sci-fi elements to be beautifully realised.
As an example of hard sci-fi Oblivion comes up lacking and I feel this has more to do with the problems of putting hard sci-fi onto film. The world is not sufficiently developed and there too many issues left hanging. The story is complete in the sense of a film but lacks the full realisation that I would expect from a novel or game. Oblivionis a strong attempt to make a hard sci-fi which works very well as a film. Whether it answers the question as to how well hard sci-fi can ever be put onto film is more difficult. In part, it illustrates the problems of hard sci-fi on film and in part it shows how hard sci-fi can benefit from being on the big screen.