In Star Wars, there are laser blasters with loud sound effects (pewpew). In Interstellar, explosions in space are witnessed in silence.
In Star Wars, spaceships travel at light speed to other galaxies. In Interstellar, a spaceship travels through a wormhole to another galaxy.
In Star Wars, a spherical robot runs cleanly on sand. In Interstellar, a rectangular robot spins like a pinwheel through two foot deep water on a planet with 130% of Earth’s gravity.
In Star Wars, a wookie gets all the chicks wet. In Interstellar, there’s a lot of dust.
Verdict: Basically the same movie.