List of plot holes I noticed.
In no particular order
-Nobody investigated at all when a gardener was admitted to the hospital with multiple stab wounds through his angles and back and razor cuts on his hands because he said "it was an accident"
-There was no investigation to Kim's disappearance.
-They didnt call the police to go and investigate the giant cavern system under the house that Kim was pulled in to (That's all that needs to be said to the police, I cant believe people are saying the police wouldnt believe them)
-Some how nobody noticed the dead monster crushed between book cases while they were cleaning up the library.
-Sally showed Alex a developing picture of her with a monster on her shoulder and he ignored her, then she seemed to forget about it and he put her to bed.
-Why didnt they take Kim to be killed or converted when she was unconscious? (not sure if plot hole)
-They attack during a brightly lit busy dinner party but not at night while she is sleeping. I guess this is necessary for the plot but kinda stupid.
I think this movie would have made a better tongue in cheek comedy horror, especially with the clumsy and not-so-intimidating monster design. I laughed all the way through it, especially when the gardener staggered through the door and said "it was an accident". Not the intent, but I still enjoyed this movie as a comedy