And it is good hard SciFi.
There are plenty of good sites that will help you understand the complex last act of the movie, so I am not going to go into it here. And since it is almost out of the theaters, I am not going to spend a long time on a review. I am going to say the film is well acted and tight in its main and subplots which are all intertwined into one overarching idea. We need to go to space. There are a few interesting side comments such as a school's curriculum being rewritten so that the moon landing is taught as the silly conspiracy theory that's been around for years. It discusses a dying Earth without using the words "climate change" or "global warming." It is also clear that is why the planet is dying.
The movie is epic in scale and clearly an homage to 2001: A Space Odyssey. Matthew McConaughey as protagonist, Cooper, is the explorer in the spirit of Dave Bowman. Cooper, in a sense, becomes the Starchild that Bowman became in 2001. At its core, Interstellar is an apocalyptic movie with a hopeful ending. As Cooper says, "We used to look up at the sky and wonder at our place in the stars. Now we just look down and worry about our place in the dirt." In 2001, Bowman announces as he enters his own wormhole, "My God - it's full of stars." Later as the Starchild in 2010 he announces, "I understand how you feel. You see, it's all very clear to me now. The whole thing. It's wonderful." The parallels and tribute to Interstellar's game changing predecessor 2001 are clear. Interstellar also maintains its own clean structure and themes without becoming a remake. It is a movie worthy of its audience.
Maybe, Interstellar will get us to look at the stars.