Goofs

When Namgoong smokes his first of the two remaining cigarettes he lights it with one of the two matches. Then a small boy steals the matches from his hand. Later when Namgoong offers Curtis the last cigarette the matches are back in the box and there are again two matches.

The bruise on Tanya's eye disappears and reappears between scenes.

The opening captions state: "Soon after dispersing CW-7 the world froze all life became extinct." but then a few moment late it follows that caption with: "The precious few who boarded the rattling ark are humanity's last survivors" If humanity had any survivors whatsoever, then by the definition of 'extinct' all life DIDN'T become extinct.

Minister Wilford states that Curtis Everett was the first person to make it from the tail to the front, while Claude, Timmy, and Andy were all seen in the tail and the engine.

Wilford congratulates Curtis for being the first human being to walk the whole length of the train; however, Claude, Wilford's assistant, is seen at the tail of the train, as well as the front. Though Claude does not travel very far into the tail section and while she has been in every car, Curtis has been to the very back of the train, making him the only person to traverse its entire length. The children taken by Claude, however, were the first people to travel along the entire length of the train.

If all life became extinct, there should be no polar bear for Yona and Timmy to spot. This scene was intentional in order to show that life outside the train was not extinct after all. The original poster clearly missed the point of the ending.

At the end of the film, Curtis reveals that he killed Edgar's mother when he was still a baby. Presumably Edgar was raised by Curtis, Gilliam and the others in the back of the train. Edgar has a strong Irish accent even though there don't appear to be any other Irish people. If he was raised on the train since infancy, his accent should reflect those around him, the majority of whom are American or English.

In the very final scene when the camera pans around Yona as she examines the landscape her breath should be visible in the cold temperature.

@ around 79 minutes just after Yona says "He's coming" the big henchman opens fire and either Namgoong Minsoo or his stunt double frantically dive out of the way to the right of screen of the bullets. This is clearly an editing error as moments later Namgoong Soo and the rest of the prisoners are already opening the next set of doors far away from the big henchman and his goons.

Railroad tracks require regular maintenance. There is nobody repairing the rails and the train would pretty quickly derail on faulty tracks, no matter how technologically advanced the train is.

Surviving for years on a single food source that is so carefully rationed would not lead to strong or plump people in the tail. If anything, their constant malnutrition would make them easy to beat in a fight. (Even director Bong Joon Ho admitted he was reticent to cast Chris Evans, thinking he was too muscular for the part.)

Curtis says that in the first month, the passengers of the back of the train had everything taken away and were locked in the metal box without food or water, and only after that month did they resort to eating each other. This would be impossible, since a human can only survive without water for about three days. Drinking urine in the absence of water would provide a few extra days of life at most, but any more than that would cause kidney failure and death.

If all life became extinct, there should be no insects to make into protein bars. Even if the bars are made from descendants of cockroaches that were on the train when it started running, there is no evidence anywhere of an unrealistically massive breeding operation.

During the night-vision battle scene, one of the henchmen refers to Mason as "Tilda", the actress' real name.