I mean, it's a Twilight Zone episode...
knockoff. Not just in style, with the narrator opening the story etc. and the episodic feel, but an actual specific episode, which was also adapted as one of the segments of The Twilight Zone movie.
Even so, it's a pretty creepy and very disturbingly weird homage. Worth seeing, if only for the atmospheric eeriness of it.
The ending is a bit muddled. Spoilers: They didn't seem able to make up their minds about how much of it was the kid's fault. Claiming he was trying to stop it right after showing his evil grinning and forcing people to kill each other isn't very convincing. Nor is his fear of the dog when he was in control. They sort of make up for it by saying at the end that he's just one of the great dangers in the world 'or it seems that way', suggesting that perhaps he is actually every and all dangers. Maybe he's god. Or the devil. Or, the story just doesn't make a lot of sense. But it leaves you feeling a vague sense of unease, which is the point.