Like Total Recall, Impostor was based on a short story by Phillip K. Dick. (Dick's stories were also the inspiration for Blade Runner and Minority Report.) In my opinion Impostor is a solid science fiction film.
The core of these stories by Dick has to do with the nature of reality and Impostor is no exception. If we have memories implanted in our minds, how can we tell what is real and what is an artificial memory? Added to this in the movie is the change in a society that comes from years of war. Can we have freedom and human rights when anyone can be a spy? This combines two great traditions in sci-fi; illusion vs. reality (Total Recall) meets taking over our minds and bodies by an alien power (Invasion of the Body Snatchers).
Add to the great story concepts is superior acting by Gary Sinise and Madeleine Stowe. The supporting cast is good with Vincent D'Onofrio playing a complex character. Is he a villain? Nothing is as it seems.
With all of these positive comments, I cannot give the film a 10/10. This is a low budget film which first started as a short film and grew into a feature. While the story of Impostor IMHO is superior in some ways to Minority Report and much better than typical sci-fi, the lack of money for Impostor shows.
The director, Gary Fleder is no Speilberg, Ridley Scott or even Paul Verhoeven. Sometimes the pace of the film seemed to need tighter editing. The script in the central part of the film could have used more work to learn more about this world. And the music was just ok in supporting the action and emotion of the film.
Still Miramax was right to decide on making this a feature film rather than a short subject or straight to TV film. Impostor has some great sci-fi story ideas and good performances. 8.5/10
