It is always difficult to rate or recommend an old movie. Especially for hard SF movies, things date really quickly and special effects seem rather silly by todays standards. Given that, this movie was rather well made, tried to predict technological advances reasonably (although I'd love to see that anti-anti-gravity device!) and had potentially a good story by Stanislaw Lem. The movie would probably have had a much better story line if it hadn't been cut in half and might have become a classic. For now, it doesn't come beyond the usual warnings about technological advancements such as nuclear bombs - although I admit that was a rather new message in the time the movie was made. Acting wasn't particular good, but no worse that other SF movies in that era.
Is it worth watching? If you like SF movies, and are not prejudiced against old "dated" effects: Yes. Not spectacular, but a good watch
Is it worth watching? If you like SF movies, and are not prejudiced against old "dated" effects: Yes. Not spectacular, but a good watch