Peter Ericson’s review published on Letterboxd :
There are no well-known actors in the movie, and that is a good thing since big-name faces would certainly have been distracting and detrimental to the movie’s image. The viewer does not get to know the characters very well, but that is not an issue for this movie as it is not so much character-driven as it is event-driven, and what they do find out about the passengers is what they would have learned had they been aboard that plane.
The movie’s depiction of the chaos and disorganization feels realistic and is believable, and not once did I think that what happened on the screen could not have happened in reality. There is, at least in my eyes, no sensationalism here; the direction is altogether professional and respectful.
"United 93" is very powerful and moving, regardless of whether or not all the facts are true and all the details correct. One particular scene that stuck in my mind is where an elderly woman is talking to someone on the phone, telling the person on the other end the combination to her safe. Watching this movie is a harrowing experience that is likely to affect the viewer not only mentally but also physically; the movie is very visceral, at times almost overwhelmingly so.
As I left the theater, I found myself wondering what my impression of the movie would have been if 9/11 had only been a part of this movie’s storyline and not actually happened. Probably quite different. The events on 9/11 did occur, however, and "United 93" is what it is: not a movie one watches to be entertained or to escape reality, but to get a documentary-style observation of some of the things that happened that day in September 2001, the day the world changed, both aboard United Flight 93 and on the ground. The movie is an appropriate memorial, ensuring that we never forget and showing us that even in the darkest and most horrific situations imaginable, there is always hope.