Despite being humorous in its outlook and providing numerous "Easter eggs" to fans of Star Wars , Aliens , Close Encounters , and E.T. (amongst others), this isn't a parody.
The rest of the film's targets are more in line with expectations, with "Star Wars," "Men in Black," "Aliens," "Back to the Future," "Close Encounters of the Third Kind," and "Mac and Me" all cited at one time or another.
Sigourney Weaver puts in a brief appearance as Mr Big and shares a scene with Blythe Danner which features one of Weaver's signature lines from Aliens , a line that earns huge laughs in Paul.
Pegg and Frost freely drop clever references to iconic modern sci-fi cinema, from Close Encounters to Aliens to, of course, E.T. (one voice cameo in particular underlines the magic that should have permeated the entire film).
"Paul" borrows heavily from so many movies -- "E.T." obviously, but also "Jaws," "Aliens," "Easy Rider" and many more -- but while it definitely takes their lines or plots, it doesn't quite replicate their emotional stakes or dramatic payoffs.
Paul, however, is a sci-fi movie spoof, half its dialogue consisting of lines lifted from Star Wars , Close Encounters of the Third Kind , Star Trek, Raiders of the Lost Ark , Aliens , Back to the Future , and all the other 70s and 80s sci-fi comfort-food staples fed to growing fanboys back then.