Justin Chang

It doesn't feel like storytelling so much as mechanical engineering.

Somewhere millions of miles from Earth, an astronaut named Ryland Grace, played by Ryan Gosling, awakens from a years-long coma to find himself all alone on an unmanned spacecraft.

The two other astronauts on board are dead, and Grace has temporary amnesia, with no idea who or where he is.

It's a fairly chilling premise on paper, but from the start, the movie plays the situation for laughs.

Grace flails and falls all over the place.

Gravity is in full effect.

But although Gosling is a nimble physical comedian, I had trouble buying his performance.

Grace might be all alone in space, but he seems to be mugging for the camera, as if he knew there was an audience watching him.

In time, Grace's memories begin to return.

In regular flashbacks, we see him back on Earth, teaching middle school science.

He's approached by a government official named Ava Stratt, a terrific Sandra Huller, who wants to recruit him for a top-secret mission called Project Hail Mary.

She knows that years ago, Grace was one of the most important molecular biologists in the U.S.,

Long story short, the sun is being devoured by aggressive microbes called astrophage.

If nothing is done, the resulting global cooling will wipe out a huge chunk of Earth's population over the next few decades.

Grace was chosen to join a crew of astronauts who would venture into deep space, seeking a solution to the astrophage problem.

Now, with his colleagues dead, he really is Earth's last hope.

Before long, the movie's ET component kicks in.

Grace meets an alien from another spaceship, who looks a bit like a crab made of sandstone, and whom he nicknames Rocky.

Rocky's home planet, Arad, is also being threatened by astrophage.

And in time, he and Grace become friends and team up to save their respective worlds.