It's unfair to say that it's a ripoff.
Just because other films have dealt somewhat with the topic doesn't necessarily mean that this film is a ripoff.
One other thread here (the comment "rip-off") gives a link to a Spanish feature.
I myself have seen a short film called, "Impulse" that deals with the same basic plot line: The apocalypse is coming, and a young man is rushing to be with the one he loves before the end.