I was leaning towards a 6 originally because I thought it was slightly above average, but unfortunately the ending was quite unfulfilling. Nevertheless I found this film generally entertaining with a few iffy choices.
The acting all around was fine. Everyone did their job and no one was negatively distracting. The only person who positively stood out was the little boy. I thought he did a great job.
Story was fine I suppose, nothing wildly original. Maybe I'm stupid, but the connection between the slap face and the monster made no sense to me, it was barley explained to begin with and is also generally just a bad title lol.
Also I found the relationship written between the older brother and the girl wildly poorly written. They had just met, then she basically lives there and then they fight like a seasoned couple. It was very confusing and weird and took me out of the story. There were a few intricacies and inconsistencies like that, that gave this an amateurish feel.
Another thing that took me out of the story was the monster. It literally looked like someone bought a mask of the witch from Snow White from party city and threw some dirt on it. It looked silly and was hard to take seriously, which was unfortunate.
I wanted to like this a lot more than I did because it did have some cool creep factor, however it was not boring or a waste of time. I would recommend... but not vehemently.