Very few horror movies would last past the second act if the characters in these films were actually fans of horror movies.
Some time after the first occurrence of Scary Old Timey Music Wafting Through the Vents, after Creepy Bugs Fluttering Inside the House and certainly by the time of the "Accidental" Fall That Sidelines a Key Character — well, that’s when any red-blooded, movie-going individual would run out the front door and never look back.
To the credit of director Andy Muschietti, his co-writing team and a first-rate cast, "Mama" succeeds in scaring the wits out of us and leaving some lingering, deeply creepy images, despite indulging in many of the aforementioned cliches — and about a half-dozen more.(Executive produced by horror master Guillermo del Toro, "Mama" is a feature-length expansion of a three-minute short that Muschietti made with his sister Barbara.) This is a very bad movie.