Protecting the earth from the scum of the universe
Why it is hard sci-fi
A comedy that earns a place on the soft end of the list. The films working idea is that contact has already happened and is administered as a federal regulatory problem. Refugees from foreign systems file paperwork. Crashed ships get classified. The neuralyzer is the films one device that handles plot mechanics by fiat. The rest is bureaucratic worldbuilding played as farce.
Science inside it
Memory editing as a public-policy tool, exotic species licensing, customs and immigration applied to non-Earth nationals. The neuralyzer is fictional but the structure of a registry-and-cover-up agency is the kind of thing a society with real first-contact would actually build.