The movie starts out good, your usual introduction to characters, know your setting, etc.
The airport they arrive at later in the movie feels very claustrophobic and plays into the horror theme well. Due to how compact it is, even when the lights were on, it felt uneasy and you never know when something is going to jump out.
My only gripe would be some of the dialogue that was written being stupid (The ending in particular between the kid and the stewardess).
Other than some badly written dialogue, I was pretty invested.