The two best parts of the movie - in addition to the powerful story of an astronaut taking a ship through a black hole near Saturn, to save the human race from ecological disaster - was the computer on the ship, and the way that going in or near a black hole slows down time, so the astronaut and crew age at at a normal rate while the people back on Earth, aging at their normal rate, age much more quickly, where hours in space equal years and decades on Earth.
The computer - TARS by name - was a worthy homage and successor to HAL of 2001, smart-talking, funny, sage, and brave. It - the computer doesn't want to be referred to as "he" - looks good as a walking rectangle with a pair of wide stilts for legs. There have been lots of computers on spaceships over the years - including Star Trek - but TARS is far and away the best.
The aging effects were beautifully done, with Matthew McConaughey putting in his best work in this movie and indeed right up there with his riveting performances on television and in the movies in the past few years. Jessica Chastain is also excellent as his daughter who becomes the same age as her father - at the same time as her father - as the plot progresses. All of this was reminiscent of Robert Heinlein's classic juvenile science fiction novel, Time for the Stars, except Interstellar situates these personal paradoxes in a much grander story.
So far, so great. The special effects were also outstanding, and better in many ways than previous state of the art movies in space like the second Star Wars trilogy. The science, too, was good, and made Interstellar, until this point, a fine hard science fiction movie - one, moreover, with real heart.
But then came the ending, which hinged on father/daughter communication across time. In this case, I saw this done far better in the father/son communication across time via ham radio in Frequency, a very well controlled, tight little movie. In the case of Interstellar, the time travel depends upon a murky interpretation of quantum mechanics, which not only verged on the mystical, as quantum mechanics always does, but withdrew the strong mix of hard science and human emotion which worked so well in the rest of the movie. Instead, we got superb emotion, but situated in an unclear, metaphysical base.
Nonetheless, I'd strongly recommend Interstellar, for the first two-and-a-half hours the movie, which were exceptional science fiction and movie-making indeed.