Logan's Run.
Michael York and Jenny Agutter live in a high technology domed city in the 23rd century, after a series of disasters have wiped out the rest of humanity. Agutter is a secret dissident, York is a "sandman" or policeman, charged with hunting down and killing all who try to escape from this "utopia", where everyone is euthanised at age 30 in a ritual called "carrousel".
Eventually the pair of them are forced to attempt an escape from the city, which brings them into some dangerous encounters.
It's very silly indeed. And it also shows just how much Star Wars was a major leap forward in special effects. In Lucas' film the plastic models don't look like plastic models, which they do here (as was also the case in Silent Running).
Politically, it's also extremely conservative. You could analyse it as a reaction against the permissive society buzz of the 1970s, and a harking back to allegedly more human, and more humane conservative American way of life.
Peter Ustinov was probably the best thing in it.
Also sci-fi's silliest robot: